Sometimes say for example you will have an excel sheet where you want to upload that from Powerapps and based on that excel sheet datecolumn values you need to update the datecolumn values in dataverse.

So sometimes in excel sheet you keep datecolumn as blank and when you update dataverse based on that column you will get error to update with a string value or some date value. In those situations we need to use few things which I will explain below.

if(equals(variables('DateColumnValue'),''),null,variables('DateColumnValue'))