How to Convert Time to Decimal Format Converting time to decimal format just involves basic division. There are 24 hours in a day, 60 minutes in an hour and 60 seconds in a minute.

Open an Excel document containing a section with time data written in "hh:mm" format, such as "12:30." Click on an open cell off to the side of the first entry in the existing data. You can use a ...

Microsoft Excel also uses fractional days within dates similar to Julian dates but called serial dates. The time of day is stored as a decimal fraction of the 24 hours clock starting from midnight.