Meshtastic system time

How exactly does it work with the delivery times of the messages.
I have the problem in a private long-fast group that messages with a time specification for the test (example: test 1:09 p.m., also sent by the test node at 1:09 p.m.) were received by the other nodes at 1:07 p.m. (also in the Message details listed as such).
So what if they arrived 2 minutes before they were sent???
I read elsewhere that at least 1 node in a private group must have an active GPS in order to generate the system time?
I also carried out the same test in the open long-fast channel and the message was also registered 2 minutes too early (and there are a number of nodes with GPS in this channel).

Another phenomenon in the private group are messages that go through a low-traffic router and only reach the other nodes 9 minutes after they were sent.
This will probably be the router’s deep sleep time.
Can someone give me explanations about this?
Thank you :smiley:

I think there’s a NTP (Network Time Protocol) server setting somewhere. This would only work if you have a TCP/IP connection, probably from a card that has WiFi or Ethernet. Alternatively I imagine that a GPS signal would provide a timestamp to the board, but I’m not certain. I don’t think the App shares it’s timestamp with the node.