B4J Question Return the Date without Slashes

I need to save a file with the date as the name.. e.g. 2019_07_30.txt but the datetime uses slashes..

So I get C:\07\30\2019.txt which is obviously not going to work..

I need to either lose the slashes or use underscores, also I need the year, then month, then day.. Anyone know how to do this?

Thanks