missing exif date inserts gap

[mac]

When batch renaming and adding the EXIF date taken - if there is no exif date I get a gap before the .suffix. Can I avoid this? (eg picture01 .jpg)

[xnview]

And you use "picture01<date taken>.jpg"

[mac]

Thanks for replying
what I mean is that some of the image files do not contain EXIF data. If I say <filename> <Date Taken [Y.m.d]> and there is no EXIF date taken I get an empty space before .jpg - Microsoft guidelines say a filename should not end with an empty space.
Maybe there is no way round this?

[xnview]

no way if you have "<filename> <Date Taken [Y.m.d]>" with a space