It is meant to fire at midnight to rotate my logs. The timer seems to never fire though, I tried setting my clock to 11:59PM and watching it hit the time.
Otherwise, a far-fetched idea of why it might not be working... I recall Nick changing the way <timer> was parsed for ImportXML due to some bug or unintended behaviour. Maybe this is some kind of regression with normal timers?
I set up your timer, and set the time to 11:59 pm, and it fired at midnight. However to test it I did a:
ResetTimer ("test") -- after renaming the timer "test"
The reason is that if you fiddle with the time it may get confused. Especially if you set the clock back to 11:59 pm it may think it has a day to go (not a minute). So by doing a ResetTimer you are making sure the day/date it is set to fire is the correct one.
The other thing I would do is print (or note somewhere) the return code from OpenLog. If it fails for some reason, the logs won't open. For example, if the path is not right.