I have no idea how these apps were calculating date display. I am a Canadian (in their settings), who was logged in via a VPN from I think the Netherlands, with a phone that was time synced to Kenya. Screenshots from iPhone August 2019.
Apps
WhatsApp
Facebook messenger
Apple messages
Gmail
Instagram
Skype
Zoom
Apple photos
Google photos
Amazon
Apple credit card
Apple health
Evernote
Google news
Audible
Google analytics
Tickets
Mostly from airlines
AirCanada
Emirates
FlightNetwork
JamboJet
Lufthansa
United
Westjet
Amtrack
Booking.com
Google Flights Screenshots
From the series Building the EHR
Section: Conventions / Date Display
