How can I change the time?

You don't. The time is set and fixed at the server. It is UTC across all stations to ensure the readings from all stations are at the proper time.

If a radiation cloud was to go across Europe, going over several time zones, and all these stations were all set to different time zones it would be a nightmare to identify it on any stations that may detect it. For instance the first station to detect it, may be at 14:23 local time, then as it moves into another time zone, the time may be 15:23, and then over another, that may be 16:23. (Obviously the minutes would change, I'm just using this as an example.) If someone wanted to check the stations the cloud had been detected with all of the times would be different and would be a really hard task converting multiple times into something universal. To avoid that, and to keep everything on a level playing field, the time is set by the server to UTC, as this is the same across the world.

I don't understand what you mean by adding the seconds? The seconds are shown on the station graph page and the control panel. All records are stored in the database with seconds. The only place I can see they aren't shown is on the graph X axis. Adding this to the graphs is unnecessary and will only make them look more cluttered. The minimum submission time is every 30 seconds (set at the server) so never more than any two records would be the same minute, and the graphs are fairly low resolution so it just wouldn't add anything, just clutter.

I can see from your readings that you are submitting every 30 seconds. This may be your setup or the server regulating the submissions.
24.7 CPM on 2025-03-21 14:27:34
24.7 CPM on 2025-03-21 14:27:04
21.2 CPM on 2025-03-21 14:26:34
21.2 CPM on 2025-03-21 14:26:04
14.1 CPM on 2025-03-21 14:25:34
28.2 CPM on 2025-03-21 14:25:04

If you are submitting more frequently than 30 seconds then you may want to adjust your submission time to a minimum of 30 seconds as any other submissions are simply disregarded. I have mentioned in earlier posts that there is effectively nothing to gain by submitting at less than 1 minute intervals. The server is set to only keep 1,000,000 records for non-donating users, and (I think) 5,000,000 for users that have donated. At 1 minute samples you will retain 1.902 years (694 days) of readings before the oldest are overwritten. Submitting every 30 seconds will only allow for 0.951 years (694 days) of readings to be stored before the oldest is overwritten.