Birthdays
Birthday countdown calculator
Count calendar days until the next occurrence of a birthday.
How to use this calculator
Enter Date of birth and Count from. Count calendar days until the next occurrence of a birthday. The answer updates when you change an input.
Understanding the result
The year of birth does not change the annual month/day countdown.
Common questions
What assumptions does this result use?
A 29 February birthday is represented as 28 February in non-leap years for this countdown.
Are intermediate values rounded?
No. The calculation retains JavaScript number precision internally and formats only the displayed result unless the stated method requires a discrete whole value.