Restrict default events to 30 minutes
Use vars for the hardcoded values of 20 and 30 that appear all the time

30px is the minimum offset of the tooltip container (i.e. like a margin around it)
20px is a CSS margin specified for the tooltip pointer.

TODO: We need to find a non-hardcoded way of specifying the tooltip pointer margin.
We can't expect all users to have a 20px tooltip pointer margin.