M31 - Print time

This command reports the time elapsed since the start of the current print job to the host. When printing from SD card, the print job timer starts as soon as SD printing starts.

If PRINTJOB_TIMER_AUTOSTART is enabled then the first M109 or M190 command received from the host will also start the print job timer.

For manual control from the host, use M75, M76, and M77 to start, pause, and stop the print job timer.