Days Between Two Dates - Weeks, Months, Years and Business Days
Pick two dates to see how many days lie between them, also as weeks and days and as years, months and days.
Maintained by Hirantha Sandaruwan Lakshan. Updated 13 October 2026.
About this tool
Choose whether to count the end date too, and see how many of the days are business days (Monday to Friday), with the option to leave out Sri Lanka's public holidays for 2026 and 2027. It runs in your browser and sends nothing anywhere.
How it works
The days counted are the dates from the earlier date up to, but not including, the later one, so 1 January to 31 January is 30 days. Turn on 'count the end date too' to include the later date as well. That gives 31 days and suits a period such as 'from 1 to 31 January, both included'. If the end date is before the start date, the gap is shown as a positive number and the tool tells you the order.
Weeks and days divide the days by seven. For years, months and days, the tool adds whole months to the earlier date for as long as they fit, using the last day of a shorter month when needed (31 January plus one month is 28 February), and counts the days left over.
Business days are the Monday to Friday dates among the days counted. With the holiday option on, public holidays that fall on a weekday are left out too. The holiday list is the one the Sri Lanka holidays page uses, taken from the Central Bank of Sri Lanka, and it covers 2026 and 2027 only. Outside those two years the tool leaves out weekends only and warns you.
Everything is counted on the calendar in whole days, so your time zone and daylight saving make no difference. Hours are 24 times the days. The tool covers the years 1583 to 9999 in the Gregorian calendar.
Worked examples
All of 2026
1 January to 31 December 2026 is 364 days: 52 weeks, or 11 months and 30 days. Count the end date too and it is 365 days, which is exactly 1 year.
Business days around the Sinhala and Tamil New Year
10 to 20 April 2026, both days counted, is 11 days with 7 weekdays. Leave out the two New Year holidays on Monday 13 and Tuesday 14 April and 5 business days remain.
An end date before the start date
From 13 October 2026 back to 1 January 2026 is 285 days. The tool shows the number as positive and says the end date is before the start date.
Frequently asked questions
How many days are there between two dates?
Subtract the earlier date from the later one. 1 January to 31 December 2026 is 364 days, or 365 if you count both days. The tool does this for any two dates from 1583 to 9999.
Should I count the start date and the end date?
It depends on the question. For 'how many days from A to B', do not count the end date. For the length of a period with both days included, such as a leave, a stay or a course, count both days. The toggle switches between the two.
How many business days are between two dates?
Business days here are Monday to Friday. Choose the Sri Lanka option to leave out public holidays on weekdays too, for 2026 and 2027. Saturday is treated as non-working, because the Central Bank's lists make every Saturday and Sunday a bank holiday, so adjust the result if you work a six-day week. The holidays are the public and bank holidays in the Central Bank's lists, which mark only some of them as mercantile holidays, so a private employer's days off can differ.
What if the end date is before the start date?
The tool swaps them for the count, shows a positive number of days and tells you the end date comes first. The years, months and days are counted from the earlier date to the later one.
Why do I sometimes get a result like 1 month and 30 days?
Months have different lengths. The tool adds whole months to the earlier date and counts the rest in days, and when the start day is 31 a shorter month uses its last day. From 31 January to 30 March 2026 that is 1 month and 30 days: 28 February, then 30 more days.
Are holidays outside 2026 and 2027 left out?
No. Only the 2026 and 2027 Sri Lanka lists are stored. For any day outside those years the tool leaves out weekends only, and it shows a warning when your range reaches beyond them.
Does the time of day matter?
No. The tool counts calendar dates, midnight to midnight, so time zones and daylight saving cannot change the answer.
Sources & references
Updated Oct 13, 2026