Date time in Filename

[mugakuno@gmail.com]

Hi! I'm trying to rename all pictures in a directory so that they include the Date and Time when they were taken. I type the following command

exiftool "-FileName<DateTimeOriginal" -d "%Y%m%d-%H%M%S%%-c.jpg" .

but I get the following warning messages

Warning: No writable tags set from ./Dos.png
Warning: No writable tags set from ./Uno.png
    1 directories scanned
    0 image files updated
    2 image files unchanged

What am I doing wrong?
Thanks

[Alan Clifford]

Does that try to rename a .png to a .jpg?

[StarGeek]

PNG files rarely have the DateTimeOriginal tag.  You'll have to use a different tag to set the filename from.  See FAQ #3 to help figure out what tag you might want to use.

Also, as Alan pointed out, your command will rename PNG files to have a JPG extension.  Try using .%%e instead of .jpg and it will save the extension from the original filename.

[mugakuno@gmail.com]

Yes, you were right, those PNG files didn't have the DateTimeOriginal tag. I've done again with jpg files and it worked.
Thank you!