Add AM/PM option

[LazaroFilm]

Please add an 12h AM/PM option to display the time.

[TheLion]

Strange. On my system the AM/PM is displayed and I want to show in 24h format ;-)

[hamadfayyad]

On my system 24h is displayed and I want to show in 12h AM/PM !!

[tvirelli]

I second this.

[AlexVerrico]

Hi Everyone.
I know that this issue is an old one, but just for anyone who finds it, I have added this functionality after taking over maintenance of the plugin. See https://github.com/AlexVerrico/Octoprint-Display-ETA
Cheers,
Alex.