dp - parse dates 822-style
/usr/lib/mmh/dp [-form formatfile] [-Version] [-help] dates ...
Dp is a program that parses dates according to the ARPA Internet standard. It also understands many non-standard formats, such as those produced by TOPS-20 sites and some UNIX sites using ctime(3). It is useful for seeing how mmh will interpret a date.
The dp program treats each argument as a single date, and prints the date out in the official 822-format. Hence, it is usually best to enclose each argument in double-quotes for the shell.
To override the output format used by dp, the -form file switch is used. This permits individual fields of the address to be extracted with ease. The file is either the name of a format file or a format string directly, if prepended with an equal sign `='. See mh-format(5) for the details.
Here is the default format string used by dp:
which says that if an error was detected, print the error, a `:', and the date in error. Otherwise, output the 822-proper format of the date.
^$HOME/.mmh/profile~^The user profile
ap(8), Standard for the Format of ARPA Internet Text Messages (RFC-822)
`-form' default as described above