Web server w03 outage outside of normal maintenance window

Hi Winhost people, I received a notification about a maintenance window, but I'm a little confuse about the date, the message said:

"
The maintenance is scheduled to take place on:


Wednesday, May 21st, 2015

Between 9 p.m. and 12 a.m. Pacific time
"
So, the maintenance is going on Wednesday 20 or Thursday 21 ?

I hope you can tell me on time to take the necesary actions.

Regards!

 

Gaddyel, it's Thursday the 21st. Sorry about the wrong day in the email.

 

Thank you!