From the linked website:

Sunday, August 5
NASA Mars Rover Landing
8:30 to 10:45 p.m. PT <--- that would be Pacific Time.
Mars Science Laboratory/Curiosity Rover Landing Coverage and Commentary #1 -
Entry Decent and Landing

The landing is scheduled for SUNDAY August 5 at 10:30 PM Pacific Daylight
Time.  Since the mission team is at the Jet Propulsion Lab in Pasadena, I
suspect that most announcements will be on west coast time.

Jim

-----Original Message-----
From: Roger Whittaker
Sent: Friday, August 03, 2012 8:07 AM
To: jr.arnott@GMAIL.COM
Cc: vanagon@GERRY.VANAGON.COM
Subject: Re: OT - Curiosity

Dear curisouser and courisiour

Your listing of time has been a questionif mine since the first announcement
every one keeps calling the landing for 1:30 am Sunday morning Florida time
.... Would that not make it 10:30 pm Saturday night vancouver Bc time ???
Rather than the Sunday night 10:30 pm you have just posted ... Darn that
Canadian rail road man and his invention of time zones :)
Regards

There must be a lifetime of thought in the last second if we are to live
from moment to moment.

On 2012-08-03, at 7:16 AM, Jim Arnott <jr.arnott@GMAIL.COM> wrote:

> Go science! Sunday 10:30 PM PDT
>
> Frank G & team – Good luck!
>
> http://www.ustream.tv/nasajpl