Indicator of "weekend exchange rate"

There was a discussion about the exchange rate and the way Curve provides information about “weekend exchange rate”. While I think that access to the current exchange rate would be useful but the implementation of this feature may be difficult, there’s another way around the problem.
I would like to have kind of indicator in the app providing users with information whether at the moment exchange rate is “standard” or “weekend”, perhaps with addition for time to the scheduled next change of it. It could be displayed at the “card in use” screen (allowing for different status for different currency pairs).
Since this information is always known to the system there shouldn’t be any problem with the implementation of this feature.