# Date Calculator: Days Between Dates, Add or Subtract Days

Count the days between two dates (in weeks, months and weekdays too), or add and subtract days, weeks, months or years to find a date. Uses Singapore time.

Interactive tool: https://lookup.sg/tools/date-calculator

## How this works
Days between dates counts calendar days from the start date up to the end date. By default the end date is not counted, so Monday to Friday is 4 days; switch on "Include the end date" to count both, which gives 5. The same span is also shown in weeks, in calendar months plus days, and as weekdays (Monday to Friday) and weekend days. Public holidays are not taken out.

Adding or subtracting moves by calendar years and months first, then by weeks and days. When the target month is shorter, the date is clamped to its last day, so 31 January plus one month is 28 February (29 February in a leap year).

"Today" is today's date in Singapore (SGT, UTC+8), read from your device. Leap years follow the Gregorian calendar: every fourth year, except century years not divisible by 400.

## FAQs
### How many days are there from 10 October 2026 to Christmas?
There are 76 days from 10 October 2026 to 25 December 2026 (not counting Christmas Day itself), which is 10 weeks and 6 days, and 54 of them are weekdays.

### What date is 90 days from 10 October 2026?
90 days after Saturday 10 October 2026 is Friday 8 January 2027.

### Should I include the end date when counting days?
Include it when both the first and last day count, such as a leave period or a hotel stay counted in days (10 to 14 October is 5 days inclusive). Leave it out to find how long until a date (10 to 14 October is 4 days away).

### How many days are in 2026?
2026 has 365 days because it is not a leap year. The next leap year is 2028, which has 366 days including 29 February.

## Sources
- [Time and Date: Singapore time zone (SGT, UTC+8)](https://www.timeanddate.com/time/zones/sgt)

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Source: Lookup (https://lookup.sg) · Data as of October 2026 · Listings compiled from Singapore government open data (data.gov.sg), OneMap and Overture Maps places. Free listings never show contact details; contact details appear only on Lookup Verified listings.