The problem with converting e. g. "1.1", or sometimes "1/1" and even "1,1" to a date is a real issue that we get from time to time, from people in different locales.
Let's take the date "Jan 1".
Currently we assume that the date separator of your locale is present in the text (string) to even consider this is a date, and sadly “Jan 1” doesn’t contain English date separator, which is “/“.
“Jan/1” would be converted correctly.
What do you need to know now?
Include a separator in Date/Time function where you want to convert text (string) to number (date).
Unfortunately, at this point we are not able to offer a 100% solution that matches 1 to 1 with Excel. But we will try to simplify it in the future.