I have noticed that twtxt timestamps differ. For example:

• @prologic@twtxt.net (and I assume any Yarn user)
  2024-09-18T13:16:17Z
  
• @lyse@lyse.isobeef.org
  2024-09-17T21:15:00+02:00
  
• @aelaraji@aelaraji.com (and @movq@www.uninformativ.de, and me)
  2024-09-18T05:43:13+00:00
  

So, which is right, or best?