Creating a solution > About choosing a field type > About timestamp fields
About timestamp fields
Use timestamp fields to store a date and time together to reference a fixed point in calendar time. Timestamps are measured in seconds.
The order in which the date and time parts appear and the separators used depend on the system formats set for the file and the display format for the field. To change the format of a timestamp field, see Formatting and setting up field objects in Layout mode and Specifying formats for timestamp fields. You must specify formats for both date and time components to change the format of a timestamp.
FileMaker Pro stores timestamps as the number of seconds since midnight on January 1, 0001. Therefore you can calculate timestamps before or after a given timestamp by subtracting or adding a number of seconds. For example, in a calculation field whose result is a timestamp, the following formula calculates the timestamp one day (60 seconds to a minute * 60 minutes to a hour * 24 hours to a day = 86400 seconds) after the value in a timestamp field named TimestampStarted:
TimestampStarted + 86400
The minimum and maximum values of a timestamp are 1/1/0001 12:00 AM and 12/31/4000 11:59:59.999999 PM.
Related topics 
Defining and changing fields
Working with data in date fields
Working with data in time fields