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AT(1)                       General Commands Manual                      AT(1)

       at - execute commands at a later time

       at time [ day ] [ file ]

       At  squirrels away a copy of the named file (standard input default) to
       be used as input to sh(1) at a specified later time.  A  cd(1)  command
       to  the  current  directory  is  inserted at the beginning, followed by
       assignments to all environment variables.  When the script is  run,  it
       uses the user and group ID of the creator of the copy file.

       The  time is 1 to 4 digits, with an optional following `A', `P', `N' or
       `M' for AM, PM, noon or midnight.  One and two digit numbers are  taken
       to be hours, three and four digits to be hours and minutes.  If no let-
       ters follow the digits, a 24 hour clock time is understood.

       The optional day is either (1) a month name followed by a  day  number,
       or  (2)  a  day  of  the week; if the word `week' follows invocation is
       moved seven days further off.  Names of months and days may  be  recog-
       nizably truncated.  Examples of legitimate commands are

              at 8am jan 24
              at 1530 fr week

       At   programs  are  executed  by  periodic  execution  of  the  command
       /usr/lib/atrun from cron(8).  The granularity of at  depends  upon  how
       often atrun is executed.

       Standard output or error output is lost unless redirected.

       activity  to  be performed at hour hhhh of year day ddd of year yy.  uu
       is a unique number.
       /usr/spool/at/lasttimedone contains hhhh for last hour of activity.
       /usr/spool/at/past directory of activities now in progress
       /usr/lib/atrun program that executes activities that are due

       calendar(1), cron(8)

       Complains about various syntax errors and times out of range.

       Due to the granularity of the execution of /usr/lib/atrun, there may be
       bugs in scheduling things almost exactly 24 hours into the future.