Fix the timezone for example dates

[tmeasday]

Issue: Unit tests were failing in Australia

(20 Jan in Australia is 19th Jan in "en-US". I know this! It is my birthday, and I have colleagues in the US!!)

What I did

Ensure a consistent created date that doesn't depend on local TZ.

[codecov]

Codecov Report

Merging #2654 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2654   +/-   ##
=======================================
  Coverage   34.34%   34.34%           
=======================================
  Files         389      389           
  Lines        8750     8750           
  Branches      902      902           
=======================================
  Hits         3005     3005           
- Misses       5129     5159   +30     
+ Partials      616      586   -30

Impacted Files	Coverage Δ
addons/knobs/src/angular/utils.js	0% <0%> (ø)	⬆️
lib/ui/src/modules/ui/components/layout/usplit.js	38.7% <0%> (ø)	⬆️
...modules/ui/components/stories_panel/text_filter.js	30.98% <0%> (ø)	⬆️
addons/actions/src/lib/decycle.js	53.52% <0%> (ø)	⬆️
addons/knobs/src/components/types/Number.js	7.93% <0%> (ø)	⬆️
lib/ui/src/modules/ui/components/layout/index.js	29.28% <0%> (ø)	⬆️
app/react/src/client/preview/element_check.js	67.64% <0%> (ø)	⬆️
...-native/src/preview/components/OnDeviceUI/style.js	0% <0%> (ø)	⬆️
addons/a11y/src/components/Report/Elements.js	0% <0%> (ø)	⬆️
addons/actions/src/lib/util/typeReviver.js	71.42% <0%> (ø)	⬆️
... and 51 more

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