I’ve noticed that rescheduling posts doesn’t work properly.
It appears to correctly reschedule the post, but not delete the previously scheduled versions. Consequently you can end up with phantom extra posts.
I’ve seen extra posts that only appear in the Micro.blog timeline, and I’ve seen extra posts that also appear on the blog. Associated extra cross posts also appear on other services.
None of the extra posts appear in the Posts listing.
Just to be clear, does the reschedule happen before the post is originally scheduled to publish? It shouldn’t be possible for it to go to the blog or cross-posting until the date hits. I’m looking into this.
I rescheduled in both directions. I made posts earlier and later, and it seems like all the phantom postings are the original schedules. The “real” posts all happened correctly, but it seems like there were things queued up for posting that weren’t removed when the schedule was changed.
Most of the phantom posts only appeared on the micro.blog timeline. Not the blog. I don’t remember re cross posts.
However the latest phantom post from today, “Ringo’s new friend” (I have already cleaned it up, sorry) posted to the blog, the micro.blog timeline, and cross posted to Mastodon and Pixelfed. It was not in the Posts listing or my list of posts in MarsEdit. To remove it I delete the micro.blog timeline post.
I’m really not clear on exactly what I did, as I queued up, rescheduled, and even deleted and readded several scheduled posts all at once. So I don’t remember exactly what I did/didn’t do for each.
I can try some more and take notes on any rescheduling etc if that will help…
This is still happening… just happened with my latest post. Every “reschedule” resulted in a post appearing on the blog, timeline, and cross post at whatever the old time was. I’ve had to clean up three or so this morning. 
Is this better handled/discussed via a help@ email, or is the forum a good place?
Here is fine. I’m still confused about how this is happening. It shouldn’t be possible for blog posts with a date in the future to make it to your blog or the timeline. I think there must be something I’m missing in how you are using this.
Are you rescheduling them on the web or in MarsEdit?
Also, one more question: can you confirm that when a post is published, the date and time is actually correct on your blog?
The process I usually use:
They then seem to post at each previously scheduled time. e.g. if I (re)schedule for in three days time, then two days time, then one days time, posts to the timeline and cross posts will appear at each of those times. Sometimes I will see a whole extra post on the rendered version of my blog.
They generally end up correctly dated etc on the rendered blog, but I have seen a few extra posts on the blog. They will have one of the previously scheduled times. If I go and investigate in the Posts listing on the web, I will only see a Post for the correct (most recently updated/scheduled) time.
I tried replicating on my test blog, but it worked properly. I wonder if it is somehow related to posts that are also scheduled for cross posting?
I’d be happy to post a test post to my real blog and see what happens… if that will help you.
In Mars Edit, with a post open, go to the Post Menu and choose Edit Date…. You can set it to a later date / time or even an earlier one. I’ve done that numerous times.