We're in the PST time zone, but when we went to schedule reservations, it seemed to assume we are in the Eastern Time Zone. We were getting "Selection not currently available" error, or "This time is in the past" errors when trying to create reservations. Andy and Josh discovered the root issue to be the .ht-inc/php5extras.php file which we changed from 'America/New_York' to 'America/Los_Angeles'. This resolved the issue and I can now create reservations successfully!
To fix it:
1. Edit /var/www/html/vcl/.ht-inc/php5extras.php to indicate the correct time zone:
2. Edit /var/www/html/vcl/.ht-inc/requests.php (line 3301 currently) to indicate the correct time zone (purely cosmetic):
print "<small>(Pacific Time Zone)</small>";
This could be fixed permanently in a config file or by checking the system time zone during the install process.