The exchange rate applied to remittances is set by MoneyGram and the amount to be received will be calculated from this rate.
Current exchange rates can be viewed using the Remittance Simulation
About the Exchange rates set by MoneyGram
Normally, the exchange rate is updated once a day. The update time is adjusted to the American Daylight Saving Time which is 1PM - 2PM in Japan time; and Standard or Winter time which is 2PM - 3PM in Japan time.
The rates, however, can be changed anytime particularly when the market is volatile.
* It the funds sent are not received for 45 days, a new exchange rate may be applied. Therefore, the receive amount may change from the amount set when the remittance was originally made.
The exchange rate applied from local currency to JPY is set by MoneyGram as well.