Actually my 4500 (1.02 firmware) displays the 24 hour clock PLUS AM/PM in the OLED...
BTW, my country is actually under day saving time (DST). In this case using the web browser the time/date functions display the correct time, but the OLED displays the time WITHOUT DST. For example:
Current time: 23:15
Browser interface: 23:15
OLED: 22:15 PM
The next firmware should correct the OLED issue (pm/am and DST info). And keep a user decision when to use AM/PM or military time, as well DATE formats (YYYY/MM/DD, MM/DD/YYYY, DD/MM/YYYY, etc). As weel to keep that configuration on the logs.