The only problem there is the times change slightly each week. Generally it's from 11am-2am GMT -8. Thursday night/Friday morning.
However the person doing the database work actually moves the snipes just as the last step before taking the database offline so as to have as little impact as possible. Thus the times are variable to within about an hour in either direction. We also sometimes do the work on a Wednesday or a Friday instead based on other factors such as holidays or perhaps a failure in the maintenance the night before, etc.