@Sarovani If your date and time drift between the two units in an HA pair is too far off you will not be able to sync configuration between the two units typically. You really should have an NTP server that is accessible by these F5s so that this doesn't occur. If they are too out of sync already you can configure NTP and then manually adjust the time of one of them to match the other, this is assuming both aren't so far off that they cannot have their time corrected automatically with NTP. Once you manually set the date and time reboot that device, assuming your configuration is in sync between the HA units and when it comes back up you should have no issues after that. If they are both so far out of sync you repeat this process for the other unit once the one you just finished updating comes back up. Having a failover event, if the configuration is in sync should be minimal if you must do this during business hours.