How to indicate unknown photo dates?

[AKH]

Ok, thanks. So I did in the past.

[Wheat]

If I recall they said put a date closest to what you remember and clarify in the comments to screens section.

[AKH]

Hi all,
possibly I missed it somewhere.
For some old slide scans I dont have the exact date, sometimes I know only month and year. How can I indicate such unknown dates when uploading a photo? Just with an additional comment?
The upload function always require a full date, once overwriting the date saved with the exif data (what would indicate the date of the scan, when scan were made with the camera)?
Thanks, AKH