Refer to the exhibit.

https://www.cisco.com/c/en/us/td/docs/routers/xr12000/software/xr12k_r3-9/system_management/command/reference/yr39xr12k_chapter4.html#wp1784026936

By default, syslog and debug messages are stamped by UTC, regardless of the time zone that device configured. You should append localtime key word to "service timestamp {log | debug} datetime msec" global command to change that behavior.

https://community.cisco.com/t5/networking-documents/router-log-timestamp-entries-are-different-from-the-system-clock/ta-p/3132258

https://www.cisco.com/E-Learning/bulk/public/tac/cim/cib/using_cisco_ios_software/cmdrefs/service_timestamps.htm