Sony XR-2600 Operating Instructions Manual page 6

Setting the Clock
The clock has a 12-hour
digital indication.
When you set minute digits
"00" comes after "59". Setting
the hour digits will not affect the
minute digits.
Pull out the DISPLAY knob to display the time
digits.
Turn to "4" while pulling out the TUNING knob.
Set the hour digits.
tens @
Turn to "#" while pulling out the TUNING knob.
Set the minute digits.
tutes @
The digits will advance in sequence. To advance them rapidly, keep
the TUNING knob turned while pulling it out.