The $wager_closing is placed for this within the WordPress admin: November 9, 2011 6:59AM GMT

That is 12:01 am PST (California Time) on November ninth. But I wish to have the ability to add an alternative choice within the admin to allow them to choose a timezone according to UTC. During my own condition it's UTC -7. I attempted this "November 9, 2011 6:59AM GMT -0700" but no go.

// Auto Close Bet
$now = time();
$bet_closing = strtotime(get_option('cp_gamble1_endtime'));
if ($bet_closing > $now) { // Betting Open!
    $output .= 'On';
    $cp_gamble1_onoff = true;
    update_option('cp_gamble1_onoff', $cp_gamble1_onoff);
} else {
    $cp_gamble1_onoff = false;
    update_option('cp_gamble1_onoff', $cp_gamble1_onoff);
    $output .= 'Over';
}

I am sure there's an easy method to get this done. If there's I am all ears :)

You should use date_default_timezone_set() function to create timezone before calling strtotime() function

Keep in mind that UTC and GMT have one hour difference in summer time.

Just examined this (I place the command and subsequently line provides the result):

var_dump(strtotime("November 9, 2011 6:59AM GMT"));

int(1320821940)

just like:

var_dump(strtotime("November 9, 2011 6:59AM GMT -0700"));

int(1320821940)

But without GMT is effective:

var_dump(strtotime("November 9, 2011 6:59AM -0700"));

int(1320847140)