Convert Date to Day Number

Date of Easter The date can be converted to the day number using the Astronomy Calculator below.  Enter the date in the format of mm/dd/yyyy or pick the date using calendar selector by clicking on the calendar icon.

The day number is a number of days to the selected date from the first of the year.  This calculator does take into account if the year is a leap year when converting the date to the day number.

Convert Date to Day Number

Background on Date to Day Number

The Date to Day Astronomy Calculator looks at the month number.  This value is then converted to the number of days in that month.  The year is determined if it is a leap year.  The number of days from the month is then added to the number of days in the month inputted to arrive at the total day number.

Astronomy Calculator Disclaimer:
These calculators are for informational and educational purposes only. Accuracy is not guaranteed and should not be used for critical calculations or navigation. Clear Sky Tonight is not responsible for any errors, omissions or misrepresentations.