redhat man page for dp

DP(8)                                                                [nmh-1.5]                                                               DP(8)

NAME
       dp - parse dates 822-style

SYNOPSIS
       /usr/lib/mh/dp [-form formatfile] [-format string] [-width columns] [-version] [-help] dates ...

DESCRIPTION
       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 nmh 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 quotes for the shell.

       To  override  the  output  format  used by dp, the -format string or -format file switches are used.  This permits individual fields of the
       address to be extracted with ease.  The string is simply a format string and the file is simply a format file.  See  mh-format(5)  for  the
       details.

       Here is the default format string used by dp:

            %<(nodate{text})error: %{text}%|%(putstr(pretty{text}))%>

       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.

FILES
       $HOME/.mh_profile          The user profile

PROFILE COMPONENTS
       None

SEE ALSO
       ap(8), Standard for the Format of ARPA Internet Text Messages (RFC-822)

DEFAULTS
       `-format' default as described above
       `-width' default to the width of the terminal

CONTEXT
       None

BUGS
       The argument to the -format switch must be interpreted as a single token by the shell that invokes dp.  Therefore, one must  usually  place
       the argument to this switch inside quotes.

MH.6.8                                                             11 June 2012                                                              DP(8)