Allow Users to Cancel or Edit reservations after they have started
Settings should be available to allow users to edit a reservation after it has started. Situations arise (ie. illness, change in plans) where it would be ideal for the user to shorten or delete the reservation to allow others to use the room.

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LCairns commented
One of the things that we found as a workaround for this is to have the user use the Check in option (appears 15 mins before the reservation). Once they check in, the box changes to Check-out. So, if I reserved a room for 8 hours and ended up not needing it at all, or needing it for < 8 hours, I can check out and it frees the room up for others to reserve.
What I do NOT agree with giving a user the option for canceling (an 'X' is displayed), but yet workplace errors out - but the user has no idea there is an error. (And of course users without the specific RESERVATION security groups assigned to their roles that would let them override other room arrangement settings that you don't want them to be able to do.)
In my opinion, the error handling in workplace is abysmal!