Citizen CB1 Series Instruction Manual page 29

Checking the time currently shown
Check whether the watch shows Summer Time or standard time.
Crown position
To change the time to show, see page 28.
Switching Summer Time and standard time
1. Pull the crown out to position
The second hand moves
and indicates which time is
currently shown.
ON Summer Time is shown
The standard time is
OFF
shown
2. Push the crown in to
position to finish the
procedure.
.
When Summer Time is
shown
27