Factory set Clock.
HONEYWELL ST9400C 7 DAY HEATING PROGRAMMER
Honeywell ST9400C 7-Day Electronic Programmer with 2-Channel & User Guide
Honeywell ST9400C 7-Day Electronic Programmer with 2-Channel
7-Day 2 Channel Central Heating & Hot Water Programmer Timer Replacement for Honeywell ST9400C – Dual Channel Wired Boiler Controller and Heating Timer