I booked some Air Canada flights (YYZ to YVR) using points from USAir Dividend Miles through Star Alliance.

The flight is late in the day.

Will I be able to go on standby for an earlier flight with these reward tickets?

Any considerations I need to keep in mind?

Many thanks in advance.

You should be able to standby; however, if they can confirm a seat for you at the time you request to take the earlier flight they will charge you $25 per ticket to take an earlier flight. On the other hand, if the earlier flight is full you can standby for free.