"Schedule" button won't appear in 4.1

Just tried to schedule 4 posts using WP 4.1 for the first time since the update, but after I set up the date and time, as I’ve done literally thousands of times before, the button remained on “publish.”

Wondering if this was a new feature in 4.1, I clicked on “publish” for one of the posts. WP went into action and told me that the post was indeed published (not scheduled), but when I checked the site, my test post wasn’t there.

If this was happening to everyone, I’d be seeing links to the problem on Google, but since I can’t find any I may be a rarity. Anyone know what could be causing this and how to fix it?

Thanks,

LB