Add the number of hours each city is ahead/behind.

Bug: 31522711
Test: Manual - 1) Honolulu (hours behind PST) 2) Barcelona (hours ahead
of PST). Set system time to Guam, Adelaide, and Sydney to see full set
of potential ahead/behind hours/minutes and tomorrow/yesterday variants.

Change-Id: I935baa4673dbe7f816967d36678c9aadf4b10d92