Advance tax in India: Due dates, Interest, and Step-by-step computation

Advance tax is one of those compliance items that founders routinely underplan. The business collects revenue, profits build up, and then the March deadline arrives with a tax bill that should have been paid in four tranches starting June. The result is interest under Sections 234B and 234C (now Sections 424 and 425 under the Income Tax Act, 2025) that compounds quietly through the year. For a company paying corporate tax at an effective 25.17% under Section 115BAA, or a founder selling secondary shares at 12.5% long-term capital gains, the interest on a missed instalment is not a rounding error. This guide covers who must pay, how to compute each instalment correctly, and where founders specifically get the calculation wrong.

What is the advance tax threshold in India, and who must pay it?

Any taxpayer whose estimated income tax liability for the year, after deducting TDS and TCS already paid or deductible, is ₹10,000 or more must pay advance tax (Section 208 of the Income Tax Act, 1961, now Section 404 of the Income Tax Act, 2025). This covers individuals, Hindu Undivided Families, partnership firms, Limited Liability Partnerships, companies, and non-residents with Indian-source income. The sole exemption is for resident senior citizens (above 60 years of age) who have no income from business or profession.

Who pays advance tax: the founder’s dual exposure

Most early-stage founders face advance tax on two fronts simultaneously, and conflating the two is where errors start.

The first is at the company level. A private limited company incorporated after April 2023 with turnover below ₹400 crore (as measured in the second preceding year, FY 2023-24 for AY 2026-27) is taxed at a base rate of 25%. If the company opts for Section 115BAA, the base rate drops to 22%, producing an effective rate of 25.17% after a flat 10% surcharge and 4% health and education cess. Minimum Alternate Tax under Section 115JB at 15% of book profit continues for companies not on the 115BAA or 115BAB track. The company files Challan 280, pays advance tax in four instalments, and books it against its corporate tax liability.

The second is at the founder’s personal level. A founder earning salary from their own company may have most of their salary tax covered by TDS that the company deducts under Section 192. But if the founder has income from other sources, whether capital gains from selling secondary shares, ESOP perquisites not fully covered by employer TDS, rental income, interest on fixed deposits, or dividend income, those sources may tip the net tax liability past ₹10,000. At that point, the founder must pay personal advance tax in instalments.

The two obligations are completely separate. Missing the company’s instalment triggers interest at the company entity level. Missing the personal instalment triggers interest in the founder’s individual ITR. The CA managing the company’s books may not automatically be computing the founder’s personal advance tax unless they have been explicitly asked to do so.

Advance tax due dates FY 2026-27

For Tax Year 2026-27 (April 2026 to March 2027), advance tax is governed by Sections 403 to 408 of the Income Tax Act, 2025. The instalment schedule is unchanged from the prior regime.

Table 1: Advance tax instalment schedule, FY 2026-27

Instalment	Due date	Cumulative percentage of total estimated liability to be paid
First	15 June 2026	At least 15%
Second	15 September 2026	At least 45% (cumulative, net of taxes already paid)
Third	15 December 2026	At least 75% (cumulative, net of taxes already paid)
Fourth	15 March 2027	100% (cumulative, net of taxes already paid)

Where a due date falls on a Sunday or public holiday, payment on the next working day is treated as timely (CBDT Circular No. 676 dated 14/01/1994, still operative by practice under the new Act). Any tax paid on or before 31 March 2027 still qualifies as advance tax for that year, but payment after 15 March triggers interest under Section 425 (the equivalent of old Section 234C) for the short period.

Presumptive taxpayers under the equivalents of Sections 44AD and 44ADA are an exception: they pay 100% of their estimated liability in a single instalment by 15 March 2027, not four. That one-instalment structure is a meaningful cash flow advantage for early-stage businesses within the eligibility window.

How to compute advance tax: the step-by-step method

The mechanics are the same for individuals and companies, though the tax rates differ. The five-step process below works for both.

Step 1: Estimate total income for the year

Do not wait until September to run this calculation. The June instalment requires a reasonable estimate of the full year’s income as of June. For a company, this means projecting the year’s revenue, deducting allowable expenses and depreciation, and arriving at estimated taxable profit. For a founder personally, it means aggregating salary (after standard deduction), estimated capital gains from any transactions already executed or planned, estimated interest and rental income, and dividend income net of any exemption.

One thing founders consistently omit: income from secondary share sales or ESOP exercises that happened in the first quarter but whose tax impact has not been quantified. If a founder sold shares in May 2026 at a significant gain, that gain must enter the June instalment calculation.

Step 2: Apply eligible deductions

For companies on the standard regime, deductions include allowable business expenditure, depreciation under Section 32, and any eligible Section 80 deductions (though companies under Section 115BAA cannot claim most exemptions and deductions). For founders personally, the new tax regime (which is the default from FY 2026-27) allows only the standard deduction of ₹75,000 for salaried income and a limited set of exemptions, whereas the old regime allows the full suite of Chapter VI-A deductions including Section 80C, 80D, and others. The advance tax computation must use the same regime the founder will use for the final ITR.

Step 3: Compute the tax liability

Apply the applicable rate to taxable income. For a company under Section 115BAA: 22% base + 10% surcharge + 4% cess = 25.17% effective rate. For a founder under the new personal tax regime (Tax Year 2026-27 rates): slabs are nil up to ₹4 lakh, 5% from ₹4 to 8 lakh, 10% from ₹8 to 12 lakh, 15% from ₹12 to 16 lakh, 20% from ₹16 to 20 lakh, 25% from ₹20 to 24 lakh, and 30% above ₹24 lakh, before surcharge and 4% cess. Capital gains from listed equity held more than 12 months are taxed at 12.5% above the ₹1.25 lakh annual exemption. Capital gains from unlisted shares (ESOP shares, for instance) held more than 24 months attract 12.5% without indexation; short-term gains from unlisted shares are taxed at slab rate.

Table 2: Effective corporate tax rates under different regimes, FY 2026-27

Entity type	Base rate	Surcharge	Cess	Effective rate
Domestic company, turnover below ₹400 cr	25%	7% (>₹1 cr income)	4%	~29.12%
Domestic company under Section 115BAA	22%	10% (flat)	4%	25.17%
New manufacturing company under Section 115BAB	15%	10% (flat)	4%	17.01%
Company subject to MAT (Section 115JB)	14% of book profit (Finance Act 2026, effective 01/04/2026)	Variable	4%	Approx. 16.24%

Step 4: Subtract TDS and TCS already paid

The advance tax payable is the estimated annual tax liability minus TDS already deducted or expected to be deducted before year-end, and TCS credits. For a company, TDS deducted by clients on professional fees (Section 194J) or contractors (Section 194C) reduces the advance tax obligation directly. For a founder, TDS on salary deducted by the company under Section 192 or Section 392 under the new Act reduces the personal advance tax payable.

If the resulting balance after TDS is below ₹10,000, no advance tax is due. If it is ₹10,000 or more, the four-instalment schedule applies.

Step 5: Split into instalments

Each instalment is a cumulative percentage of the full-year estimated liability, not a sequential slice. The second instalment is 45% minus whatever was already paid in the first. The third is 75% minus what has been paid in the first and second. This means if income estimates change mid-year, the subsequent instalments adjust.

Worked example: founder-run SaaS company, FY 2026-27

Estimated taxable profit for the year: ₹80 lakhs Tax regime: Section 115BAA (22% + 10% surcharge + 4% cess) Effective rate: 25.17% Estimated total tax: ₹80 lakh x 25.17% = ₹20.14 lakhs TDS expected from clients during the year: ₹3.00 lakhs Advance tax payable: ₹20.14 – ₹3.00 = ₹17.14 lakhs

Instalment	Due date	Cumulative percentage	Amount due
First	15/06/2026	15% of ₹17.14 L	₹2.57 lakhs
Second	15/09/2026	45% of ₹17.14 L, minus ₹2.57 L paid	₹5.14 lakhs
Third	15/12/2026	75% of ₹17.14 L, minus ₹7.71 L paid	₹5.14 lakhs
Fourth	15/03/2027	100% of ₹17.14 L, minus ₹12.85 L paid	₹4.29 lakhs

Treelife note: Treelife’s compliance calendar automatically generates these instalment amounts from the company’s quarterly MIS. Founders who do not have an active MIS setup routinely miss the June and September instalments because they are still in the middle of the financial year and their accountant has not run a projection. Get the MIS connected early. The Treelife Compliance Calendar for FY 2026-27 covers every advance tax due date alongside your other corporate filings.

Presumptive taxation and advance tax: what founders misread

Founders who run a company through the standard corporate route pay all four instalments. But solo founders and early-stage professionals who have opted for presumptive taxation under the equivalent of Section 44AD (turnover up to ₹3 crore where cash receipts are below 5% of total) or Section 44ADA (gross receipts up to ₹75 lakh for specified professionals) pay advance tax in a single instalment by 15 March 2027.

This is a legitimate cash flow advantage, but it comes with constraints. First, the five-year lock-in: once you opt into the Section 44AD equivalent, you must continue for five consecutive tax years. If you declare profit below the 8% (or 6% for digital receipts) deemed rate in any year within the five-year window, you are barred from re-entering presumptive taxation for the next five years, and you face mandatory audit under Section 44AB if your total income exceeds the basic exemption limit. Second, the scheme is not available to companies or LLPs. It applies to individuals, HUFs, and partnership firms only. Third, a tech founder providing software consultancy is a “specified professional” under Section 44AA and must use Section 44ADA, not Section 44AD.

The single-instalment benefit of presumptive taxation does not eliminate the Section 234C risk. If the full liability is not paid by 15 March, interest accrues on the shortfall.

What does Section 234B interest cost you?

Section 234B of the Income Tax Act, 1961 (Section 424 of the Income Tax Act, 2025 for Tax Year 2026-27) applies when a taxpayer has paid less than 90% of the total assessed tax liability by 31 March of the financial year. Interest under this section runs from 1 April of the following year (the first month of the assessment year) until the date the balance tax is actually paid.

The rate is simple interest at 1% per month or part of a month. Any fraction of a month is counted as a full month (Rule 119A of the Income Tax Rules).

Worked example: Section 234B

Total assessed corporate tax liability for FY 2026-27: ₹50 lakhs Advance tax paid during FY 2026-27: ₹40 lakhs (80% of liability) 90% of ₹50 lakhs = ₹45 lakhs

Since ₹40 lakhs is less than ₹45 lakhs, Section 234B applies. Shortfall: ₹50 – ₹40 = ₹10 lakhs Company pays the balance on 30 September 2027 (6 months after 1 April 2027). Interest: ₹10 lakhs x 1% x 6 months = ₹60,000

That ₹60,000 is a dead cost with no business return. It simply compensates the government for the use of money that should have been paid earlier. For a company with ₹2 crore in advance tax exposure and a 6-month gap, the interest alone crosses ₹12 lakhs.

What does Section 234C interest cost you?

Section 234C (Section 425 under the Income Tax Act, 2025) is charged when the cumulative advance tax paid by a specific due date is below the prescribed percentage of the final assessed liability. Unlike Section 234B, which runs from April 1 onwards, Section 234C interest is charged for a fixed period tied to each instalment: three months for the first, second, and third instalments, and one month for the fourth instalment.

Table 3: Section 234C interest computation, applicable percentages and periods

Instalment	Required cumulative percentage	Interest period if below threshold
15 June	12% (corporate assessee) / 15% (individual/other)	3 months
15 September	36% (corporate) / 45% (other)	3 months
15 December	75%	3 months
15 March	100%	1 month

Note: Corporate assessees had a different percentage applied for the June and September instalments under old Section 211 of the Income Tax Act, 1961. The distinction in percentage between corporate and non-corporate assessees was applicable specifically for those first two instalments. Verify the exact applicable percentage under Sections 407 and 408 of the Income Tax Act, 2025 with your CA before computing, as the Income Tax Rules, 2026, which govern the operationalisation of the new Act, are being progressively notified.

The formula in all cases is: interest = 1% per month x shortfall amount x number of months.

Worked example: Section 234C, individual founder

Estimated total personal tax for FY 2026-27 (company route, old Act section numbers used for comparison): ₹24 lakhs Required by 15 September: 45% = ₹10.8 lakhs Advance tax actually paid by 15 September: ₹6 lakhs Shortfall: ₹4.8 lakhs Section 234C interest: ₹4.8 lakhs x 1% x 3 months = ₹14,400

If the same founder also misses the December instalment: Required by 15 December: 75% = ₹18 lakhs, minus ₹6 lakhs paid = ₹12 lakhs due Advance tax actually paid by 15 December: ₹9 lakhs Shortfall: ₹3 lakhs Section 234C interest on December default: ₹3 lakhs x 1% x 3 months = ₹9,000

Interest accumulates across all missed instalments and is computed automatically by the ITR system at the time of filing. Founders who wait to pay everything in March and then file in July are surprised to find a Section 234B and 234C interest line that was not in their budget.

Capital gains and the Section 234C safe harbour

This is the provision that most founder-facing blogs miss entirely.

The first proviso to Section 234C(1) of the Income Tax Act, 1961 (retained in substance under the new Act) provides that no interest under Section 234C is charged on a shortfall arising from underestimation or failure to estimate: capital gains, dividend income, lottery or gambling income, or income from a business started for the first time in that year.

The condition is that the advance tax on such income must be paid in full in the immediately succeeding instalment, or if such income arises after the December instalment, by 15 March.

What this means in practice for founders:

A founder who sells secondary shares in August 2026 and generates ₹1.5 crore in capital gains could not have included that gain in the June instalment. As long as the full tax on that ₹1.5 crore gain is included in the September instalment (or at least in the December instalment if the sale occurred after September), no Section 234C interest is charged on the shortfall attributable to that gain. But Section 234B still applies at year-end if the total advance tax paid, including the capital gains tax, is below 90% of the full liability by 31 March 2027.

Similarly, a founder who exercises ESOPs in October and the company deducts TDS on the perquisite value does not need to have included that in the June or September instalment. The ESOP-related capital gains from any subsequent share sale must be included in the next instalment following the sale, or by 15 March.

The safe harbour does not remove the obligation to pay. It removes the Section 234C penalty on the timing of payment for those specific income types, provided payment is made in the next available instalment.

What changed under the Income Tax Act, 2025

The Income Tax Act, 2025 came into force on 1 April 2026 and governs Tax Year 2026-27. The advance tax framework is structurally the same but has been renumbered and reorganised. Key points for founders:

The instalment schedule, the 15% threshold trigger, the cumulative percentages, the 1% interest rate, and the ₹10,000 threshold all continue without substantive change. The concept of “assessment year” has been replaced by “tax year,” meaning the income year and the assessment year are now the same period. This removes the prior-year lag in terminology but does not change what income is taxable.

Table 4: Section mapping, Income Tax Act 1961 to Income Tax Act 2025

Provision	Old Act (1961)	New Act (2025)
Advance tax liability threshold	Section 208	Section 404
Instalment schedule	Section 211	Sections 407 and 408
Interest for non-payment of 90%	Section 234B	Section 424
Interest for deferment of instalments	Section 234C	Section 425
Interest for late ITR filing	Section 234A	Section 423

ITR returns for FY 2025-26 (AY 2026-27), due in July 2026, continue to be filed under the Income Tax Act, 1961. Advance tax payments for Tax Year 2026-27, starting with the June 2026 instalment, are governed by the new Act. Both portals operate concurrently on the e-filing portal.

How does a DPIIT-recognised startup’s advance tax work with Section 80-IAC?

Section 80-IAC gives an eligible startup a 100% deduction on profits for any three consecutive years within the first ten years from incorporation, subject to DPIIT recognition, an Inter-Ministerial Board (IMB) certificate, turnover below ₹100 crore, and incorporation between 1 April 2016 and 31 March 2030 (window extended by Finance Act, 2025).

If a startup claims the Section 80-IAC deduction for a given year, its taxable profit drops significantly or to zero. That directly reduces the advance tax obligation for that year. A startup generating ₹80 lakhs in profit and claiming 80-IAC in full has estimated taxable income of nil, estimated tax of nil, and no advance tax obligation (as long as TDS credits cover any other income).

Two important caveats. First, 80-IAC and Section 115BAA cannot run simultaneously. The company must elect one. If 115BAA was opted for before 80-IAC was activated, the 80-IAC deduction is not available. The decision of which regime to enter, and when, is a structural one that should be made at incorporation or before the first profitable year; for that analysis in full, see Treelife’s guide on startup tax structuring in India. Second, the 80-IAC deduction is based on the IMB certificate, and the certificate does not automatically apply. The startup must claim it in the ITR. The advance tax computation for the year should reflect this by projecting the deduction into the estimate.

A founder who does not account for 80-IAC in the quarterly advance tax calculations will overpay advance tax and then claim a refund at ITR filing. Overpayment is not penalised, but it ties up working capital for months.

Common mistakes that cost founders real money

Mistake 1: Treating advance tax as only the company’s problem

Many founders ask their company’s accountant to manage the company’s advance tax and assume their personal liability is fully covered by the salary TDS. If they have even one equity secondary sale, one ESOP exercise with subsequent share disposal, or rental or FD income above the TDS threshold, there is a separate personal advance tax obligation. The cost of missing three instalments on ₹30 lakhs in capital gains is approximately ₹27,000 in Section 234C interest alone, plus a potential Section 234B hit if the year-end position shows a shortfall.

Mistake 2: Computing advance tax on last year’s income

The advance tax liability is based on estimated current-year income, not the prior year’s assessed income. A startup that grew 3x in FY 2026-27 compared to FY 2025-26 cannot use the prior year’s tax liability as the advance tax base. The resulting shortfall will trigger both Section 234B (if year-end advance tax is below 90%) and Section 234C (for each instalment where the cumulative percentage falls short).

Mistake 3: Ignoring the instalment if the company has losses

A company generating losses does not pay advance tax on those losses. But if the company also has income taxable as Minimum Alternate Tax (because book profits under Section 115JB exceed the MAT threshold even when there is a business loss), advance tax is still payable on the MAT liability. Founders of high-investment, high-depreciation companies, particularly those with significant fixed assets or R&D write-offs, should check MAT applicability before assuming zero advance tax.

Mistake 4: Paying the fourth instalment late and treating it as equivalent to 15 March

Tax paid between 16 March and 31 March still qualifies as advance tax for that year. But if the 100% threshold was not met by 15 March and Section 234C interest applies for the one-month period, that interest cannot be avoided by paying on 20 March. The one-month clock starts from 15 March. Plan the fourth instalment for early March, not late March.

Mistake 5: Not recomputing after a large mid-year transaction

A large equity sale in October changes the advance tax picture materially. The December instalment must be recomputed to reflect the capital gains from that sale. If the December instalment does not include the additional tax, the shortfall will attract Section 234C interest for 3 months. The capital gains safe harbour only protects timing, not permanent omission.

Frequently asked questions

Q: What is the minimum tax liability for advance tax to apply?
A: If your estimated income tax liability for the year, after deducting TDS and TCS, is ₹10,000 or more, you must pay advance tax (Section 404 of the Income Tax Act, 2025, equivalent of old Section 208). Below ₹10,000, no advance tax is required, though you still pay the full tax amount at the time of ITR filing.

Q: What interest rate applies for missing an advance tax instalment?
A: Simple interest at 1% per month, or part of a month, on the shortfall amount. This applies under Section 234C (Section 425 under the new Act) for missing quarterly instalments, and under Section 234B (Section 424 under the new Act) for failing to pay at least 90% of the total liability by year-end.

Q: Can a founder use the prior year’s tax liability as a safe estimate for advance tax?
A: No. Advance tax is computed on estimated current-year income, not the prior year’s liability. If actual income is significantly higher than the prior year, using the prior year figure will result in a shortfall and trigger Section 234C interest. The prior year figure is not a statutory safe harbour in India, unlike in some other jurisdictions.

Q: My company has claimed the Section 80-IAC profit deduction. Do we still pay advance tax?
A: If Section 80-IAC reduces your taxable income to zero or below the tax threshold, the advance tax obligation is correspondingly nil or reduced. However, companies subject to Minimum Alternate Tax under Section 115JB must pay advance tax on MAT liability even if business income is zero after Section 80-IAC. Section 80-IAC and Section 115BAA cannot be claimed simultaneously.

Q: Does Section 234C interest apply if I miss an instalment due to unexpected capital gains?
A: No, provided you pay the full tax on the capital gains in the immediately following instalment. The first proviso to Section 234C(1) exempts capital gains (and dividend income) from interest under Section 234C if the shortfall is attributable to underestimation of those specific income types and the balance is paid in the next instalment, or by 15 March if the gain arises after December. Section 234B interest at year-end still applies if the total advance tax paid falls below 90% of final assessed liability.

Q: What is the advance tax obligation for a company under Section 115BAA?
A: The same four-instalment schedule applies: 15 June, 15 September, 15 December, and 15 March. Section 115BAA changes the rate (22% base, 25.17% effective) and removes eligibility for most deductions and MAT applicability, but does not alter the advance tax timing or percentage requirements.

Q: I opted for presumptive taxation under Section 44AD. Do I need to pay advance tax in four instalments?
A: No. Taxpayers on the Section 44AD or 44ADA presumptive scheme pay advance tax in a single instalment by 15 March. However, if you fail to pay by 15 March, Section 234C interest runs for one month on the shortfall. And if the full liability is not paid by 31 March, Section 234B interest applies from 1 April. The single-instalment option is a convenience, not an exemption from interest.

Q: How does ESOP TDS interact with my advance tax obligation?
A: When your employer deducts TDS on the perquisite value at the time of ESOP exercise, that TDS is credited against your total tax liability. If the TDS covers your entire estimated annual tax liability (including any planned ESOP-related capital gains from a share sale), no additional advance tax is required. If you sell ESOP shares and generate capital gains not covered by employer TDS, those gains must be included in the subsequent advance tax instalment, with Section 234C relief available on the timing if the gain arose after an instalment date.

Q: For a DPIIT-recognised startup that defers ESOP perquisite tax under Section 80-IAC and Section 192(1C), how does this affect the employee’s advance tax?
A: The startup deferral under Section 192(1C) postpones TDS on the ESOP perquisite to the earlier of: the share sale, the employee leaving the company, or 48 months from the end of the relevant assessment year. While the deferral is active, no TDS is deducted, so no credit appears. The employee’s advance tax obligation for that year does not include the deferred perquisite. Once the deferral trigger event occurs and the tax becomes due, it is treated as the employee’s obligation in that year.

Q: What happens if I overpay advance tax?
A: Overpayment is credited against your final tax liability. If total advance tax paid exceeds the assessed tax, the excess is refunded by the Income Tax Department, typically within a few months of ITR processing. No penalty applies for overpayment. The refund carries interest under Section 244A at 6% per annum for the period of excess payment.

Q: Are non-resident founders with India-source income required to pay advance tax?
A: Yes, if their net Indian tax liability after applicable TDS exceeds ₹10,000. Non-resident founders who receive salary from an Indian company (with TDS deducted), and also have dividend income or capital gains from Indian assets not fully covered by TDS, may have a residual advance tax obligation. Double Taxation Avoidance Agreement provisions and foreign tax credit positions must be factored in before computing the liability.

Q: What is the last date to pay tax and still have it treated as advance tax?
A: Any tax paid on or before 31 March of the financial year qualifies as advance tax. Tax paid on or after 1 April is treated as self-assessment tax (paid with the ITR) and does not eliminate Section 234B interest on any year-end shortfall.

Regulatory references:

• Income Tax Act, 1961: Sections 208, 211, 234A, 234B, 234C (applicable for FY 2025-26, AY 2026-27)
• Income Tax Act, 2025: Sections 403 to 410 (advance tax liability and instalment schedule); Sections 423, 424, 425 (interest provisions); Section 404 (₹10,000 threshold); applicable from Tax Year 2026-27 (1 April 2026 onwards)
• Section 115BAA, Income Tax Act, 1961: concessional corporate tax regime at 22%
• Section 115BAB, Income Tax Act, 1961: concessional rate of 15% for new manufacturing companies (production commencement deadline of 31 March 2024, effectively closed to fresh entrants)
• Section 115JB, Income Tax Act, 1961: Minimum Alternate Tax; rate reduced from 15% to 14% of book profit by Finance Act 2026, effective 01/04/2026
• Section 80-IAC, Income Tax Act, 1961: 100% profit deduction for eligible DPIIT-recognised startups; incorporation window extended to 31 March 2030 by Finance Act, 2025
• Section 44AD, Income Tax Act, 1961: presumptive taxation for eligible businesses, turnover up to ₹3 crore (95% digital); single advance tax instalment by 15 March
• Section 44ADA, Income Tax Act, 1961: presumptive taxation for specified professionals, gross receipts up to ₹75 lakh (95% digital)
• Section 192 / Section 392 (Income Tax Act, 2025): TDS on salaries including ESOP perquisites
• Section 192(1C): ESOP perquisite tax deferral for eligible DPIIT-recognised startups
• Rule 119A, Income Tax Rules: rounding of months for interest computation
• CBDT Circular No. 676 dated 14/01/1994: next working day relief when due dates fall on holidays