TimeZone in ISO string {new Date().toISOString()}

[woodix2023]

How to display ISO date and time string taking into account TimeZone?

[jberezin]

I created option/select controls where the user could pick their timezone and pick their DST Type (USA,EU, or None).

I saved those options using arduinojson.

Then I add the timezone value to the iso time hours and add one more ( Hour++) if they are currently in Daylight savings time.

A simpler way may have been to use this branch: #278 but I am not sure because I didn't see that merge request until I had finished implementation.