Originally Posted by
julian2002
True = 12 hour hand is adjustable interdependently from the other hands in 1 hour jumps. This allows you to set the '24 hour GMT hand' to your home time zone (or UTC if that's your bag) and then adjust local time without losing minute or second accuracy (minutes and seconds don;t hack when adjusting the hour). Another way to think about this is that home time is displayed by the 24 hour, minute and second hands and are adjustable as a whole, local time uses the traditional hour hand and is adjustable separately in 1 hour jumps. Date is usually tied to local hour hand and is not quick set.
Desk = normal adjustment of local time (i.e. minutes / seconds stop when adjusting time). 24 hour hand is adjustable sperately
True is useful when travelling, especially to multiple time zones as it allows the local time to be set quickly and read traditionally, and home time to be read via 24 hour time for reference. Desk is useful when in an office and you need to track another time zone i.e. you may be working closely with the american branch, here, home time can be read traditionally with the 2nd time zone used to make sure you are not calling colleagues in the middle of the night.
Both are useful in their own way I just happen to find the 'True' GMT complication more evocative.