What do you mean make them the same? Both are strings, not datetimes. Datetimes don’t have a format - they store a value. Just like how numeric datatypes don’t have formats. You apply a format when outputting them as a string.
If you want to parse strB into a datetime, you do it the same way, but provide the format for strB.
DateTime.ParseExact(strB,“mm.dd.yyyy”,System.Globalization.CultureInfo.InvariantCulture)