More often than not, I've noticed that in a smaller environment (ie not a corporate network or server farm where you've got an IT culture) they'll rarely tell you up-front that you're going to be on-call.

One place I worked at didn't tell me there'd be 24h on-call until after I'd moved my family 800 miles. Oh, and it was an hourly position, with no stipulations for "on call". Yeah, that whole situation was fun.

Not sure the last time you used Bugzilla but you can currently track time, entering an estimated time and updating the actual time as you go.

You can also configure when you want to get emails based on what fields change and your relationship to the bug (Originator, Assignee, or watching).

Bugzilla is the only system that I have ever "liked" to work with. I have used several commercial systems as well as several large scale home grown systems over the last 20 years. All the others were slow and cumbersome and most are based on the belief that developers can't be trusted to update the bugs appropriately. This leads to way too many controls on the developer. Bugzilla on the other hand is much better about assuming that we want to do what is best and want a system to document our progress and help communicate among the team.