scale the provided value by 1024, 1024^2 or 1024^3 respectively.
The scaled value is put into `unsigned_long_var`.
-`OPT_DATE(short, long, ×tamp_t_var, description)`::
- Introduce an option with date argument, see `approxidate()`.
- The timestamp is put into `timestamp_t_var`.
-
`OPT_EXPIRY_DATE(short, long, ×tamp_t_var, description)`::
Introduce an option with expiry date argument, see `parse_expiry_date()`.
The timestamp is put into `timestamp_t_var`.