Sony PMC-DR45 Operating Instructions Manual page 24

Setting the clock (continued)
To change the display to the daylight saving time
(summer time) indication
Press and hold SUMMER TIME for 2 seconds.
"SUMMER ON" appears in the display for a few
seconds.
To cancel the summer time indication
Press and hold SUMMER TIME again.
"SUMMER OFF" appears in the display for a few
seconds.
24
The Timer