"Within 45 days", "30 working days", "7 business days after receipt" — contracts and statutes count days differently, and the difference decides whether a payment is late, a notice is valid or a delivery has missed its SLA. This calculator counts working days between two dates (excluding Sundays, optionally Saturdays or alternate Saturdays, national holidays and the festival holidays you pick), and also adds N working days to a start date to find a deadline. It runs in your browser and includes Indian national holidays for every year.
Two modes
- Days between: enter a start and end date; get the number of working days, weekends and holidays in the range, inclusive or exclusive of the end date.
- Add working days: enter a start date and a count; get the resulting date, skipping non-working days. Useful for "deliver within 10 working days" or "reply within 15 working days".
Choose the weekend pattern: Sundays only (most shops), all Saturdays (offices, banks partially), or second and fourth Saturdays (banks and many government offices). Tick national holidays (Republic Day, Independence Day, Gandhi Jayanti) and add your state or company holidays for festivals — Diwali, Holi, Eid, Pongal — which vary by year and state.
Where the count matters
- Section 43B(h) and the MSMED Act: payments to micro and small suppliers are due within 45 days of acceptance (15 days without a written agreement) — calendar days, not working days. Interest at three times the RBI bank rate runs after that; compute it with the late payment interest calculator and read Section 43B(h): the 45-day payment rule.
- GST: due dates are calendar dates and are not extended for holidays; the GST filing calendar shows them.
- Cheque bounce notices under Section 138: a demand notice within 30 days of the return memo, 15 days for payment, complaint within 30 days after that — calendar days. See Cheque bounce: the 30-day notice, 15-day window.
- Consumer refunds under the e-commerce rules: "within a reasonable time", often stated as 7–10 working days in refund policies.
- Bank strikes and holidays disrupt clearing; the bank strike business continuity plan shows why counting bank working days matters for payroll.
How to use the calculator
- Pick the mode: between dates or add working days.
- Enter the dates (or the start date and number of days).
- Set the weekend pattern and holiday options; add custom holidays for your state.
- Read the result — working days, and a list of the holidays that fell in the range so you can justify the count to a counterparty.
- Copy the deadline into your contract, PO or notice.
Drafting tips
- Say "calendar days" or "working days" explicitly in every contract clause; ambiguity defaults to calendar days in most interpretations.
- Define the weekend and the holiday list ("as per the RBI holiday list for Maharashtra") so both parties count the same way.
- For SLAs, state the time zone and the cut-off hour ("received before 5 pm IST counts as that day").
- Build buffers: a 10-working-day delivery promise in late October may span Diwali; check with the calculator before committing.
Related tools
- Late payment interest — interest after the 45-day window.
- GST filing calendar — statutory due dates by scheme.
- Notice period calculator — last working day arithmetic.
- Leave balance calculator — working days for leave requests.
- Purchase order — put clear delivery and payment day-counts on POs.