NEC systems SL1000, SL1100, SV8100 and SV9100
Using the Daylight Savings Setup program, these systems can automatically adjust the system time for daylight savings time/standard time changes.
However should it be necessary to adjust the system time on the above systems
1. Press Speaker.
2. Dial 828.
3. Dial two digits for the hour (24 hour clock, 13 = 1:00 PM).
4. Dial two digits for the minutes (00~59).
5. Press Speaker to hang up.
For clocks on Windows PC based NEC applications used in conjunction with the above systems - these should of course adjust automatically for Daylight Saving.