Can you dial the gate?

If yes, you already have a pretty reliable way of measuring time, because a stargate will stay activated for 38 Minutes (see SGA Episode "38 Minutes" for details) if nothing passes trough.

So you dial the gate to a random address, make a sundial(see nitsua60s answer) with that measurement. And voila, you have a (rough) way to measure time on this planet.

Can you dial the gate? Ether with the DHD(Dial-Home-Device, or the round thing with the many buttons with constellations on them next to the gate), or if thats deactivated/missing and you're in the Milky Way Galaxy you can manually dial the gate (Pegasus Gates don't have that feature) by turning the ring by hand (but be aware that you have to General O'Neil a power source).

If yes, you already have a pretty reliable way of measuring time, because a stargate will stay activated for 38 Minutes (see SGA Episode "38 Minutes" for details) if nothing passes trough.

So you dial the gate to a random address(could take some time to find a working one though), make a sundial(see nitsua60s answer) with that measurement. And viola, you have a (rough) way to measure time on this planet.

Can you dial the gate?

If yes, you already have a pretty reliable way of measuring time, because a stargate will stay activated for 38 Minutes (see SGA Episode "38 Minutes" for details) if nothing passes trough.

So you dial the gate to a random address, make a sundial / etc with that measurement. And voila, you have a (rough) way to measure time on this planet.

Can you dial the gate?

If yes, you already have a pretty reliable way of measuring time, because a stargate will stay activated for 38 Minutes (see SGA Episode "38 Minutes" for details) if nothing passes trough.

So you dial the gate to a random address, make a sundial(see nitsua60s answer) with that measurement. And voila, you have a (rough) way to measure time on this planet.