There doesn't appear to be a way to set a regional date/language format using the 1Password website. It would be great if there was a way to select a regional format so that dates are displayed correctly. At this time they appear to be shown in an American format of MMM DD, YYYY whereas in other places the format used is typically DD MMM YYYY. Hopefully this option can be added in a future release.
I can't comment on how the dates are displayed in the apps as I've yet to setup my account in the app, but I'm assuming it honours the regional format like the previous 'offline' vaults did.
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