How to Count the Number of Days Between Two Dates
Days between = end date - start date (in days). From 2026-01-01 to 2026-05-29 is 148 days. To include both endpoints, add 1 (149 days).
Open the interactive Everyday Lifestyle tool →Formula: days = end_date - start_date
Key facts
| Formula | days = end_date - start_date |
|---|---|
| 2026-01-01 to 2026-05-29 | 148 days |
| Inclusive of both ends | add 1 day |
| 1 week | 7 days |
| 1 common year | 365 days |
Frequently asked questions
How many days are between two dates including both?
Take end - start in days, then add 1. From 2026-01-01 to 2026-05-29 exclusive is 148; inclusive is 149.
How do I handle leap years?
Count actual calendar days. A leap year (e.g. 2024) has 366 days because February has 29.
How many days until a future date?
Subtract today from the target date. From 2026-05-29 to 2026-12-31 is 216 days.
Related pages
Days Between Dates is part of Everyday Lifestyle on GOAT Lab — a free reference you can use without signing up, and it works offline. Open the tool above for any custom value.
Part of GOAT Lab — 26 free, browser-based science, engineering and developer tools. No sign-up.