Date Data Type Structure

CitectVBA Programming Reference > Understanding CitectVBA Language Basics > Date and Time Handling > Date Data Type Structure

Date Data Type Structure

The date data type structure in CitectVBA is a junction of two very different methods of data storage. It is formed from the serial concatenation of a date-value followed by a time-value, separated by a floating point, and stored in an 8-byte floating-point date data type value.

The integer (whole) portion of the value represents the number of days elapsed since December 30, 1899.
The remainder (fractional) portion of the value represents the elapsed portion of the day since midnight.

The integer (date-value) portion (to the left of the floating point) and the remainder (time-value) portion (to the right of the floating point) must be handled differently as they are structured very differently. CitectVBA has a number of pre-defined date and time functions to convert between the internal floating-point date data type format and visibly recognisable dates and times.

Note: Dates in CitectVBA are based upon the Gregorian Calendar.

For example, the date and time of 5/22/97 at 3:00 p.m. would be stored in CitectVBA as 35572.625 representing the 35572 days since 12/30/1899, and 3:00 p.m. as 625/1000 of a full day.

Note: Don't confuse Date data types used in CitectVBA with date and time values used in Windows, DLLs, CitectSCADA, or in Cicode. For instance, CitectSCADA stores time/date-related variables as a single integer representing the number of seconds since 01/01/1970.