Chris

Thanks for the insights, can be applied to other system, where the number 0 is not 01Jan1960.

BTW we do not have to rely on the GMTOFF() function. Since SAS9.4 we have the following functions:

TZONEOFF Function Returns the user time zone offset.
TZONES2U Function Converts a SAS date time value to a UTC date time value.
TZONEU2S Function Converts a UTC date time value to a SAS date time value.