Canon EOS 80D Instruction Manual page 206

F: Bulb Exposures
Bulb timer
Elapsed exposure time
If you press the shutter button completely and then let go while the bulb

timer is operating, the bulb exposure will stop.
Doing any of the following will cancel the bulb timer (reverts to

[Disable]): Set the power switch to <2>, switch to movie shooting, or
change to a shooting mode other than <F>.
206
Set the desired exposure time.
3
Select the hour, minute, or second.

Press <0> so <r> is displayed.

Set the desired number, then press

<0>. (Returns to <s>.)
Select [OK].
4

The set time will be displayed on the
menu screen.
 When you exit the menu, <p>
will be displayed on the LCD panel.
Take the picture.
5
 Press the shutter button completely,
and the bulb exposure will start and
continue until the set time elapses.
To cancel the timer setting, set

[Disable] in step 2.