Correct time/date of the Checkpoint servers.

[chaymosphere]

I would like to verify in regards with the NTP Server, is it normal that some logs are being received in advance?

I also want to verify once I configure the "set time and date automatically using NTP", is it safe to change this during production or downtime should be expected?

[peter_schumache]

You can define the ntp Servers  any time without any downtime.

For further reference look at the following SKs:

sk83820
sk92378
sk92602

[PhoneBoy]

NTP will "skew" the clock toward the correct time.
However if the delta between system time and what NTP says is substantial (forget the exact threshold, but I think it's over 10 minutes), NTP will not touch the system clock st all.
Before you enable NTP, head to expert mode and use the ntpdate command to do a one-time sync with your favorite NTP server.
Then enable NTP and life should be good.