What does :: (double colon) mean in DOS batch files?

Question

I found this program http://baiyunmanor.com/blog/work/get-current-date-time-in-dos-batch-file/

But I don\'t know what does the line

:: datetime.bat
<         


        

Answer 1

As mentioned by acdcjunior Labels and :: have a special logic and can cause problems in parenthesis blocks

Here are couple of samples

Sample 1

IF 1==1 (
  ::
)

Output of sample 1

) was unexpected at this time.

Sample 2

IF 1==1 (
  ::
  ::
)

Output of sample 2

The system cannot find the drive specified.