prism_calc_newdate (date, date_incr, ierror)
This routine adds a time increment of date_incr seconds to the date given as In argument and returns the result in the date as Out argument. The time increment may be negative. The time structure PRISM_Time_Struct object is defined as a Fortran type of the form
Type PRISM_Time_Struct
Double Precision :: second
integer :: minute
integer :: hour
integer :: day
integer :: month
integer :: year
End Type PRISM_Time_Struct