I just had a prepaid charge by InterContinental Hyde Park on my Chase IHG card, being recently converted from Visa to MC. Just called Chase, confirmed it was a GBP transaction.

The transaction date is Apr 9, the posting date is Apr 11. Does someone know which date's conversion rate will Mastercard use on this one? Since my card is a USD card, the transaction happened in UK, which date will it use, US date or UK date? 8 hours can make it jump into another day.