For Half-Life: Zombie Edition, the precise run start is when the map zem1 loads.

• bind a key (here noted as "x") with the following command:

bind "x" "map zem1; bxt_hud_timer 1; bxt_timer_reset; bxt_timer_start;bxt_autorecord run"

"map zem1" = this loads to the precise beginning of the run "bxt_hud_timer 1" = showing the (in-game) timer on your in-game screen "bxt_timer_reset" = this will reset your timer in case it's still running from a previous attempt "bxt_timer_start" = this starts the timer "bxt_autorecord run" = this automatically records demos even if you save and load (they will end up in your zombie folder)

• if you don't record your run, a screenshot of the stopped timer will be required (you can use the snapshot command in-game or use an external program to take a screenshot)