How Excel Stores Dates and Times

Microsoft Excel stores dates as sequential numbers which are called serial values starting with January 1, 1900.

To see the serial value for today’s date and time, type =NOW() into a cell and then change the cell’s format to Number.

Excel stores times as decimal fractions because time is considered a portion of a day. So, noon is .5 and 6am is ..25.

The serial date-time for January 10, 2010 at 6am is 40188.25.