Find command with regex

Question

File I want to find.

20200521-285353-rpi3-4497-00-0-13-0-0-0-0-n.jpg
Files with Date in the filename from 2020-01-01 to 2020-09-31

not

20201021-*.*

My regex string:

^20200[0-9][0-3][0-9]-[0-2].*

Find version: find (GNU findutils) 4.7.0-git

I can't find a combination that works. My attempts:

find . -type f -regextype grep -regex '20200[1-9]-*.*'

find . -type f -regex '^20200[0-9][0-9][0-9]\-[0-2].*'

find . -type f -regextype sed -regex '^20200[0-9][0-9][0-9]\-[0-2].*'

Answer 1

Use a glob and keep it simple

find -type f -name '20200521-*'

Answer 2

If  you  want  to  find  only  20200521-285353-rpi3-4497-00-0-13-0-0-0-0-n.jpg, use

find . -type f -name 20200521-285353-rpi3-4497-00-0-13-0-0-0-0-n.jpg

If you want to find files whose names look like

YYYYMMDD-

followed by

         0, 1 or 2

followed by

                  (something)

where YYYY is 2020, use

find . -type f -name '2020[01][0-9][0-3][0-9]-[0-2]*'

but be aware that it will match false positives like 0231 (February 31), 0400 (April 0), 1038 (October 38) and 1701 (the first day of the 17th month).  If you want to find files whose names look like the above, but only for January (01) through September (09), excluding October, November and December (10, 11 and 12), use

find . -type f -name '20200[0-9][0-3][0-9]-[0-2]*'

Note that the above all end with * and not .*.

Please edit your question to clarify what you want to find.

And by the way, what is 285353?  It isn’t a valid HHMMSS.