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, &int_var, description)`::
- Introduce an option with date argument, see `approxidate()`.
- The timestamp is put into `int_var`.
-
-`OPT_EXPIRY_DATE(short, long, &int_var, description)`::
+`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 `int_var`.
+ The timestamp is put into `timestamp_t_var`.
`OPT_CALLBACK(short, long, &var, arg_str, description, func_ptr)`::
Introduce an option with argument.