Add a command that allows you to tell the bot "I'll go to the lab later, at X", something like /going 16:30 (feel free to choose another command name).
Then, when people do /inlab, show these entries too.
Remove these entries on these conditions:
Users cancel them (with another command or a special parameter or whatever)
Users is in lab and time is after the scheduled time. E.g. I may be in lab at 10.00 and have a /going 16.00: don't delete it, since I may leave at 11.30 and come back at 16.00. But if I'm in lab at 16.01 there's no need to tell that I'll be there in the past.
After some time that (30 minutes? 1 hour?): if I have a "I'm going in lab at 11.30", don't delete it at 11.30, wait at least a few minutes: I may be leaving a classroom and it takes a few minutes to get to the lab and log in, while people may be spamming /inlab frantically, they need to know that someone will be there soon
Add a command that allows you to tell the bot "I'll go to the lab later, at X", something like
/going 16:30(feel free to choose another command name).Then, when people do
/inlab, show these entries too.Remove these entries on these conditions:
/going 16.00: don't delete it, since I may leave at 11.30 and come back at 16.00. But if I'm in lab at 16.01 there's no need to tell that I'll be there in the past./inlabfrantically, they need to know that someone will be there soon