Days calculator

What this tool counts

A days calculator answers two questions: how many days lie between two dates, and which date is a number of days, weeks, months or working days away. It counts on the real calendar, with leap years, so 1 Feb to 1 Mar 2028 is 29 days and 31 Jan plus one month is 28 Feb (29 in a leap year).

By default the count stops the day before the end date, the way most people count time between two events: 17 Oct to 18 Oct is 1 day. Leave and hotel stays are often counted by days used instead, where both the first and last day count. Turn on Count the end day for that.

Kavitha’s notice period

Kavitha works in an IT office in Coimbatore. She resigns on Saturday 17 October 2026 and her contract asks for a 90-day notice period. With Add or subtract, 90 days from 17 Oct 2026 is Friday 15 January 2027, the day before Pongal week. Her manager asks how many working days that is: the tool shows 64 working days, Mon–Fri, between the two dates, before holidays.

She then turns on Working days and picks Central govt holidays, because her client follows the central list. Diwali on 8 Nov 2026 falls on a Sunday, so it costs nothing, but Dussehra (20 Oct), Guru Nanak’s Birthday (24 Nov) and Christmas (25 Dec) are on weekdays. She also adds 2 days of leave in Other days off.

How the tool works it out

1. Days between is the end date minus the start date, in calendar days (plus one when you count the end day).
2. Weeks and days divides that by 7. Months and days steps month by month on the calendar, like an age: 15 Aug to 15 Sep is one month whatever its length.
3. Working days counts every day that is not a weekend day: Saturday and Sunday for a Mon–Fri week, only Sunday for a Mon–Sat week. Holidays from the chosen list that fall on a working day are left out; holidays on a weekend are shown in the table but cost nothing. Other days off come off last.
4. Add or subtract moves the date. Days and weeks are plain days; months and years move on the calendar, and when the day does not exist in that month (31 Jan + 1 month) it lands on the month’s last day. Working days steps one day at a time and skips weekends, holidays and your days off.

The holiday lists

• Central government (Delhi and New Delhi offices): the 17 gazetted holidays for 2026 from the Department of Personnel and Training order F.No. 12/2/2023-JCA of 3 July 2025, and the 17 for 2027 from its order of 16 July 2026. Central offices outside Delhi follow 14 compulsory holidays plus 3 picked by their state’s coordination committee, so their list differs slightly.
• Tamil Nadu: the 2026 list for state offices and banks from G.O. (Ms.) No. 708 (November 2025): Pongal, Thiruvalluvar Day, Uzhavar Thirunal, Tamil New Year, Ayutha Pooja, Deepavali and others, 23 in all here. The 1 April annual closing of accounts is a bank-only holiday and is left out. The 2027 list usually comes out in November; until then, 2027 dates are counted without Tamil Nadu holidays.
• My own list: your company’s or school’s holidays, one date a line.

Id, Muharram and Milad-un-Nabi depend on the moon, and governments sometimes move them a day at short notice. The lists here were taken from published copies of the orders in October 2026.

Common mistakes

• Counting the end day by habit. 1 to 31 March is 30 days between, but 31 days if both ends count. Notice periods and loan interest usually count days between; leave usually counts both ends.
• Treating a month as 30 days. “Three months” from 30 November is 28 February, 90 days later, not 30 Feb.
• Forgetting the Saturday rule. Banks close on the second and fourth Saturdays; many shops and schools work six days. Pick the week that matches.
• Using one state’s holidays for another. Tamil Nadu’s list has Pongal and Ayutha Pooja; Delhi’s has Holi. Check which list your office follows.
• Legal deadlines. Courts and the Limitation Act have their own rules for the first day and for court holidays. Use this tool as a guide and confirm with the rules.