Hi Mita,
You could check the migrator activity in the resource manager log. In the system admin client, for your resource manager, set "Logging level" to "Performance" and in the "Context filters" field enter the word migrator, and save the changes. With this logging setup, when the migrator does some work, you should see lines in the resource manager log for the migrator. This is not the same as debug logging, and it is ok to use it without impacting other operations performance.
Note that if there are no objects pending migration, you would not see any log entries. If there are objects to migrate, you should see a line with "getMatureMigrationTasks" in it at the beginning of the cycle, and at the end of each cycle you would see "Migration cycle complete". Cycles might repeat. You could then check the log entry timestamp which is in GMT.