How to change uptimeAt timeZone

[z560]

How to change the “Mon Dec 07 2015 22:10:56 GMT-0500 (EST)” to different timezone?
I try to use $(time timezone $(twitch $(channel) “{{uptimeAt}}”)), but command return now.

Example for Normal Usage

$(twitch night)
would result in

Night is currently live playing Super Mario Kart at 720p, 60 fps with 64 viewers since Mon Dec 07 2015 22:10:56 GMT-0500 (EST) (4 hours, 3 minutes, 50 seconds) - http://www.twitch.tv/night

Nightbot Docs Twitch:
https://docs.nightbot.tv/commands/variables/twitch

Nightbot Docs Time:
https://docs.nightbot.tv/commands/variables/time

[am_1]

$(eval uptimeAtString = `$(twitch $(channel) "{{uptimeAt}}")`; uptimeAt = new Date(uptimeAtString); isNaN(uptimeAt) ? `Unable to parse the date/time $(channel) went live (or started playing a playlist)` : `$(channel) has been online since ` + uptimeAt.toLocaleString("en-us", {timeZone: "America/Chicago"}))

Replace America/Chicago with your timezone (https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#List).