Hey Wilfred!

 MK>> @RFC-3339:  2020-11-12 14:58:25-08:00

 WvV> Missing the TZUTC flag! ;-)

It's in there along with other very useful information.  Check this out;

-={ ':read !TZ=UTC date --rfc-3339=sec --date="2020-11-12 14:58:25-08:00"'
starts }=-
2020-11-12 22:58:25+00:00
-={ ':read !TZ=UTC date --rfc-3339=sec --date="2020-11-12 14:58:25-08:00"'
ends }=-

Much better.

Life is good,
Maurice

... Se ðe ear gifeð and eft oftihð... bysmer he gewyrceð.
    He who gives and takes it back again does a shameful thing.
--- GNU bash, version 5.0.18(1)-release (x86_64-motorshed-linux-gnu)