Excel date times are almost identical to OLE/COM automation date times (that used in many Windows applications).
Which means that dates are 1 unit apart, and:
- Weeks = 7
- Days = 1
- Hours = 1/24
- Minutes = 1/(24*60) or 1/1440
- Seconds = 1/(24*60*60) or 1/86400
That way you can easily add one hour to a date/time value by adding 1/24.
Source: How to quickly add hours/minutes/second to date and time in Excel?
Related:
- Firebird – adjusting Delphi stored TDateTime (or OLE Automation date) fields that contain Dates, Times or DateTimes
- [WayBack] How to Work With Dates Before 1900 in Excel
–jeroen