I have exact the same problems with a relative date campaign.
It’s really hard to handle because a normal user don’t know about the bugs and problems with these date issues in mautic. So maybe the complete campaign approach will not work for such use cases.
Maybe it is better to handle these relative date emails also not in a campaign but with different segment emails (same approach as mentioned at Send daily newsletter in mautic (with monthly campaign)? - #5 by iparker)?
Best regards,
Timo