FormattedDateTime

Accepts Date, Temporal.Instant, Temporal.ZonedDateTime, or an ISO 8601 string via value. No Intl: en (and any locale other than fi/sv) renders YYYY-MM-DD HH:MM; fi/sv render D.M.YYYY HH:MM, identically. includeWeekday prefixes an abbreviated weekday name.

• locale="fi", value=ISO instant string: 5.8.2026 20:30
• locale="en", value=Temporal.ZonedDateTime: 2026-08-05 20:30
• locale="sv", value=ISO instant string: 5.8.2026 20:30
• locale="en", includeWeekday: Wed 2026-08-05 20:30
• locale="fi", value=null (renders nothing):

Calling formatDateTime() directly: 5.8.2026 20:30