Measure with if function should return value in date format

Dear all,

I am trying to create cards on my dashboard which show "nothing" whenever there is a BLANK value in my original measure.

For that purpose I use the combination of IF and ISBLANK.

I managed to do this with several calculated measures but fail when trying it with a date.

The measure can no longer be turned into a date format whenever the IF funktion is giving the result.

Earliest Start Date = if(isblank(min(Opportunities[StartDate])),"",min(Opportunities[StartDate]))

-> Returns value with no possibility to turn into date format

For a part of the measure, the date value is being returned in date format:

Earliest Start Date = min(Opportunities[StartDate])

-> Returns value in date format

I am hoping for a workaround if there is no straight solution in Power BI.

Thank you in advance and have a great rest of the day!

Cheers,

Lisa