Sometimes it would help a lot if there was one special format string which should be applied to some Date/DateTime values within the report which should be different than the culture settings of the format. Creating a calculated field (e.g. $DateFormatString: Calculated field = "dd-MMM-yyyy": String) with the wanted format string and using this instead of the const string at each function call (e.g. "dd-MMM-yyyy" looks like this:
DATEFORMAT(
SESSIONTODAY(),
'$DateFormatString'
)

But it leads to the following error:
No overload for function DATEFORMAT matches the input parameters


Reason: The functions DATEFORMAT and DATETIMEFORMAT
https://docs.microsoft.com/en-us/dynamics365/fin-ops-core/dev-itpro/analytics/er-functions-datetime-dateformat
https://docs.microsoft.com/en-us/dynamics365/fin-ops-core/dev-itpro/analytics/er-functions-datetime-datetimeformat
second argument "format" allows const strings only, variables are not possible so far.


Please change the functions in that way that variables are possible too.