How to calculate year progress
A precise formula for calculating year progress in code or a spreadsheet.
Use two boundaries
Define the start as midnight on January 1 and the end as midnight on January 1 of the next year in the same time zone. Progress is elapsed duration divided by total duration.
Time zones matter
The year begins at different instants around the world. Use the viewer's local time zone for a personal clock or state a fixed zone for a shared reporting system.
Avoid common errors
Do not assume every year has 365 days, and do not mix UTC dates with local times. Decide whether your output updates by second, minute or completed day.
Related year guides
- How much of the year has passed? — Calculate the exact percentage of the current year that is complete.
- Leap years explained — Learn the Gregorian leap-year rule and why February sometimes has 29 days.
- What day number is today? — Understand ordinal dates and find today's position in the year.