oiler

Update at once all of the Settings -> General -> Time Zone options of your WordPress network.
This plugin was written specifically for a network that has been around for many years and was set up before WordPress 2.8 fixed the daylight savings time issue. Back then, setting the local time for your blog depended on UTC offsets only, so daylight savings folks were off by an hour for half a year. Then WordPress introduced time zones by city and the problem was solved. But we had all our blogs still with the UTC offset in use. So rather than update them individually, this plugin was written to run once and then move on. Recommended use: upload to your mu-plugins folder, run it once and then delete.

Update Time Zones Across Network

Automatically change the time zone for all of the blogs on your multisite network. Not for single installations. WPMU / Multisite / Network only.

Emanuela Castorina

This plugin in a multisite installation shows the ID of the current site/blog in the admin bar menu. The ID of the current site/blog is linked to the site info page. 
It adds also a custom column with site id information inside the sites list table. 
It can be installed only on a multisite.

Wp Show Site ID

This plugin in a multisite installation shows the ID of the current site/blog.

Update Time Zones Across Network vs Wp Show Site ID