How it works
Find the ordinal day from 1 to 365 or 366. Leap days are included automatically.
ordinal day = days since January 1 + 1
Worked example
Show example inputs and result
Calendar date: October 8, 2026.
- Result
- 281
Questions and answers
Why are some results rounded?
Results display up to 8 decimal places. Calculations use the unrounded values; very small values use scientific notation. JavaScript floating-point arithmetic can introduce tiny rounding differences.
Are my inputs sent to a server?
The calculator processes inputs in your browser. Its code does not send your values to a server.
Method reviewed: October 8, 2026 · Methods & accuracy