$WBDCALC is available for use with all WBSP commands.
startdate - starting date/time value
offset - number of intervals to be added to or subtracted from startdate
interval - interval of time to be added to or subtracted from startdate
Valid values are:
S - seconds
M - minutes
H - hours
D - days
operator - for addition set operator to + (plus sign), for subtraction set it to - (minus sign)
New date value created by adding or subtracting the offset number of intervals to/from startdate.
After running this example, the resulting page in browser should look like this: