I have a Primary and Secondary CUCM's. The Primary CUCM gets its time from my Domain Controller and the time is correct on it. The time on my Secondary CUCM is set to get its time from the Primary CUCM. But when checking the System parameters, the secondary CUCM is off by about a little over 2 minutes. apparently that is where my Cisco phones get their time is from the secondary CUCM.
How do I get my Primary and Secondary in sync regarding time? I believe that is also affecting the delay in the Voice Mail message light on the phone.
Looks like issues with both server, i would suggest to switch to a linux based NTP see below.
Below is the link for SRND which clearly states Windows NTP is not supported.
Cisco recommends synchronizing Unified CM with a Cisco IOS or Linux-based NTP server. Using Windows Time Services as an NTP server is not recommended or supported because Windows Time Services often use Simple Network Time Protocol (SNTP), and Linux-based Unified CM cannot successfully synchronize with SNTP.
(Rate if it helps)