[Timestamp Tweaks] Abolute ISO form setting doesn't use local timezone, so the UTC setting is incorrect

[NekoAlosama]

Currently in EST or UTC-4.

Relative time

The absolute ISO form doesn't use my local timezone, technically causing a UTC-4 to UTC+0 conversion.

The UTC setting assumes that the absolute time from before is correct, and then applies the correction from UTC-4 to UTC+0. This is starting from UTC-0 because the previous toggle didn't fetch my local timezone, so a UTC+0 to UTC+4 correction occurs.