How can I examine the contents of /etc/localtime?

The most appropriate command would appear to be zdump.

$ zdump /etc/localtime 
/etc/localtime  Wed Aug  7 23:52:25 2013 EDT

$ zdump /usr/share/zoneinfo/* | tail -10
/usr/share/zoneinfo/Singapore    Thu Aug  8 11:52:48 2013 SGT
/usr/share/zoneinfo/Turkey       Thu Aug  8 06:52:48 2013 EEST
/usr/share/zoneinfo/UCT          Thu Aug  8 03:52:48 2013 UCT
/usr/share/zoneinfo/Universal    Thu Aug  8 03:52:48 2013 UTC
/usr/share/zoneinfo/US           Thu Aug  8 03:52:48 2013
/usr/share/zoneinfo/UTC          Thu Aug  8 03:52:48 2013 UTC
/usr/share/zoneinfo/WET          Thu Aug  8 04:52:48 2013 WEST
/usr/share/zoneinfo/W-SU         Thu Aug  8 07:52:48 2013 MSK
/usr/share/zoneinfo/zone.tab     Thu Aug  8 03:52:48 2013
/usr/share/zoneinfo/Zulu         Thu Aug  8 03:52:48 2013 UTC

You can also interrogate these files using the file command:

$ file /etc/localtime 
/etc/localtime: timezone data, version 2, 4 gmt time flags, 4 std time flags, no leap seconds, 235 transition times, 4 abbreviation chars

$ file /usr/share/zoneinfo/Singapore
/usr/share/zoneinfo/Singapore: timezone data, version 2, 8 gmt time flags, 8 std time flags, no leap seconds, 8 transition times, 8 abbreviation chars