How to convert Julian dates

The Julian date is the number of days since the start of the Julian era, 1st January 4713 BC. For example, the Julian date 2460941 corresponds to 22nd September 2025. Julian dates aren’t very human-friendly, but they have a number of advantages for use with computers:

• they are unambiguous (unlike 01-01-01)
• they are compact to store (one integer)
• you can easily find the number of days between 2 dates by subtraction (no worrying about days per month and leap years)

Consequently they are widely used in many different application areas including: science and engineering, manufacturing, military and goverment.

Easy Data Transform can easily convert columns of values between Julian dates and standard (human readable) dates.

• use the JulianDayToDate operation in the Calculate transform to convert a column of values from a Julian date (integer) to a new column of dates in yyyy-MM-dd format
• use the DateToJulianDay operation in the Calculate transform to convert a column of values from yyyy-MM-dd format to a Julian date (integer)
• use the DateTime Format transform to convert between different standard date formats, for example from yyyy-MM-dd to dd/MM/yyyy or vice versa.
• use the Remove Cols and Reorder Cols transforms to delete and re-order columns

See the video above for a simple example of converting from a Julian date to dates in yyyy-MM-dd, MM-dd-yyyy and dd-MM-yyyy formats, and back to Julian date.

Easy Data Transform can also convert to and from Unix epoch timestamps.

As well as converting between various date formats, Easy Data Transform can help with cleaning, blending, filtering and analysing your data. All without coding. Download the free trial and try it yourself.