You need to change your phones date back to march 8th and you can set
the Chromecast back up. Once it is set back up, it will download the new
firmware. Don't forget to change the date back on your phone when done!
If you have factory reset your Chromecast, set your phone manually to
march 8th and you can set it up like normal. Once it is set up, your
device will get the firmware update! Don't forget to change your phone
back to the current date afterwards!