Schedule content to automatically expire and change at a certain time, and notify people of expiration.
That's the "Any+Time" date / time picker:
Make sure you have enabled the datepicker in the plugin's settings.
Yes. As of Version 0.9.7, Content Scheduler should work on WordPress Network Sites.
Check the plugin setting's "expiration period" and make sure you have waited at least that long before checking your content for expiration.
Make sure you have actually visited a page on your website after the post's expected expiration date. WordPress only fires off scheduled tasks when people actually visit the site.
Check your WordPress installation Timezone, and use one of the timezone strings. That is, when set to "UTC -6," our testing team found WordPress was going to wait several hours before beginning to check schedules. However, setting timezone to "America/Chicago" (the same timezone) fixed the problem. We're still checking on the reason for this.
Try simply deactivating the plugin and reactivating it, then testing again.
Other plugins that schedule events might handle scheduling incorrectly, thereby removing Content Scheduler's expiration period. Again, deactivating and reactivating Content Scheduler should re-instate the scheduling.