The ical format allows dates like DTSTART;TZID=Europe/London:20230901T201000
Whether your calendar software will let you choose how it expresses the timezone and whether the recipient's calendar software will store it that way is another question...
Google Calendar does, at least. It even supports representing events that being and end in different timezones (like a plane flight or a cross country trip)
Whether your calendar software will let you choose how it expresses the timezone and whether the recipient's calendar software will store it that way is another question...