Can I edit a changeset comment?

As subject. I have added some information using JOSM, but forgot to change the comment, so it has uploaded with the same comment as my previous edit. Not that it matters too much, but can I edit the comment to better reflect what I did?

As long as the changeset is not closed (and it will autoclose 1 hour after your last upload) you can change the changeset comment. Change some object/tag so there is something to upload, and then upload that with the new changeset comment.

If the changeset is closed, that’s it. It’s immutable now.

So if I do a second upload within the hour it will treat it as part of the same changeset? I see. Too late for that one, now, but thank you.

You can keep a changeset open for 24 hours, and for every upload to the changeset, you can write a new comment, which will overwrite the previous comment. Just don’t forget to upload something within 1 hour of a previous upload, or the changeset is autoclosed by the server.

JOSM’s current default is to keep the changeset open, and you have to go to Changesets tab in the upload dialog, to force it to switch to a new changeset (or one of other open changesets you may have).