Delay execution within a batch file for a specified number of milliseconds with the free open source sfk sleep command for Windows, Mac OS X and Linux.

sfk sleep time[s|m|h]

delay execution for a number of milliseconds,
seconds, minutes or hours.

with just a numeric value, milliseconds are used.

since sfk 1.9.9 sleep also accepts:
   1s  or 1sec  is one second.
   1m  or 1min  is one minute.
   1h  or 1hour is one hour.

web reference

usage example:

   start sfk sleep 3000 +tail -f logs\access.log -pat "GET * 404 "

      creates an error log viewer, and runs apache in parallel.
      sfk will wait 3 seconds before tail goes active.