Quote from: thoste on December 13, 2024, 08:46:32 AM

1.) Ok, if the history tab in Electrum shows the timestamp of the first confirmation:
   Where can I see INSIDE Electrum when I sent initially the transaction to the mempool?

   Again: TWO timestamps are required: initial sent (to mempool) and 1st confirmation.
   I guess a (new) column "sent time" in History tab is missing. At least optionally
   That should be feasible in Electrum.

   I don't need absolute exact timestamps. Timestamps +/- 30 seconds would be acceptable.

The closest is the "locktime (height)" which is the tip (top block height) when you created the transaction.
But that block height may have been the already tip 10minutes (on average) before you created the transaction so it not a good indication of the broadcast time.
Like I've mentioned, you need a "timer", a real-time of that.

On the other hand, a proposal can be requested to Electrum's GitHub Repository as a new feature request issue.
But I doubt the niche use-case isn't worth it for the development plus additional feature that most of the users wont even use.
You're welcome to post it though.

Quote from: thoste

2.) The blocktime is a timestamp without a reference time zone and therefore useless.

Useful actually, the time in blocks are just continuously counting number not represented by any time zone.
Technically; in "Unix Epoch time", Wiki: Epoch (Refer to Unix Epoch)
In Electrum's GUI and blockexplorers, it's just conveniently converted to your machine's local data/time.