Maintenance for the week of November 18:
• PC/Mac: No maintenance – November 18
• ESO Store and Account System for maintenance – November 19, 9:00AM EST (14:00 UTC) - 6:00PM EST (23:00 UTC)
• PlayStation®: EU megaserver for maintenance – November 19, 23:00 UTC (6:00PM EST) - November 20, 17:00 UTC (12:00PM EST) https://forums.elderscrollsonline.com/en/discussion/668861
The game won't launch if you haven't updated to the current patch. You will get an error message telling you that your client is outdated. If you're able to play, you have the update.
You can also tell by using the launcher. If you see the "update" button, you don't have the current version. If you see the "play" button, you do.
Edited by Reverb on March 21, 2016 4:50PM
Battle not with monsters, lest ye become a monster, and if you gaze into the abyss, the abyss gazes also into you. ~Friedrich Nietzsche