Excel has two different date systems. One starts in 1900, the other in 1904. That is why the number is different.
I believe neither of those formulas is correct. The second one has a few typos but the first one is just not right.
Using a -1 in the DATE function will give you a warning triangle. It works but -1 is an out of range value.
In Excel's 1900 date system, 1/1/1900 is day 1. Excel also coded in a nonexistent leap year in 1900. Both have to be taken into consideration. The correct formula for dates starting in March 1900 is
=DATE(1900;1;1)-2+A1
Some regions use a semicolon vs a comma to separate parameters in functions. If you use a comma (not decimal point) as a decimal separator you will use a semicolon in functions.
There have been an awful lot of Excel date questions/post lately. I wonder if a recent release broke the conversion of Excel dates more than it already was.