This morning I came into the office to find the Cisco 7940 phone has the correct date, but the time is a hour off (a hour slow). Now I do have DST setup within 3CX 12.5 (Phone Provisioning > General > Daylight Saving Time) and the set date to change back to regular time is correctly set (Nov 1, 2015). So the phone itself shouldn't have adjust the time just yet. Now in the SIP cnf file it seem the settings are wrong. #Setting for Timezone and DST, Option GMT,CET,EET,BT,IT,ZP4,AFG,ZP5,IST,ZP6,SUM,WAST,HST,JST,CAST,EAST,EADT,NZST,IDL,NT,AHST,IMT,YST,PST,MST,CST,EST,AST,NST,BST,AT,WAT sntp_server: "10.0.1.1" sntp_mode: unicast time_zone: "PST" dst_offset: 1 dst_start_month: March dst_start_day_of_week: Sun dst_start_week_of_month: 8 dst_start_time: 01 dst_stop_month: Oct dst_stop_day_of_week: Sun dst_stop_week_of_month: 8 dst_stop_time: 02 dst_auto_adjust: 1 time_format_24hr: 1 date_format : M/D/Y Now I'm not trying to fix the above, but my question is, i have an NTP server, can I just disable the DST setting in 3CX and the Cisco Phone and allow the NTP to adjust the time correctly?