After updating a record, some date/time fields are set to 1969-12-31Issue After updating a record, one or more date/time fields display the value 1969-12-31, which may seem unexpected or incorrect.SymptomsA date/time field (e.g., time_worked, start_date, end_date) displays 1969-12-31 or a similar time-stamped value.The behavior often occurs when setting a date/time field to empty (null) through a script or update.In certain time zones, the displayed value includes a time offset (e.g., 1969-12-31 19:00:00).ReleaseAll Supported Releases All modules using date/time fieldsCauseThis behavior stems from how date/time fields are stored and interpreted internally in ServiceNow: Date/time fields are stored as the number of milliseconds since 1970-01-01 00:00:00 GMT, also known as the Unix epoch. If a field is null and not explicitly cleared or properly initialized, the system may interpret it as zero milliseconds. Zero milliseconds = 1970-01-01 00:00:00 GMT. Time zone adjustment:If your user profile is in a negative GMT offset (e.g., Eastern Time), the system adjusts the displayed value by subtracting the time zone offset, resulting in a display of 1969-12-31. Client Script BehaviorA client script sets a date/time field to empty on mobile/tablet, and it displays as 1969-12-31 19:00:00.Null Date InitializationA GlideRecord update leaves a date field null, and the system renders it as the Unix epoch in the user’s timezone.Resolution To prevent this behavior: Always explicitly handle date/time fields when updating records: Use field.setDisplayValue('') for clearing via GlideForm.Use field = null or field = '' appropriately on the server side depending on context. Avoid leaving date/time fields unintentionally null if you expect them to be unset without showing the epoch date.Consider adding validations or default values where necessary to prevent zero-millisecond interpretations.Related LinksClient Script: Setting a Date/Time field to empty returns 1969-12-31 19:00:00Rendering issues when time_worked is set to less than epoch date