Humminbird 500 SERIES 596C - Manual (Page 66)

58 Setup Menu Tab
Date Format
(Advanced, International only)
Date Format changes the date format used by the unit. This menu option is
available in International Models only and when the User Mode is set to
Advanced (see Main Menu: User Mode).
Date Format selects the format for the date display when Time + Date is
selected as a Digital Readout on the Sonar View (see Setup Menu Tab: Select
Readouts).
To change the Date Format:
1. Make sure the User Mode is set to Advanced, then highlight Date
Format on the Setup main menu.
2. Press the LEFT or RIGHT Cursor keys to change the Date Format.
(mm/dd/yy, dd.mm.yy or yy.mm.dd, Default = mm/dd/yy)