Warning: date(): it is not safe.........

I had to move one of my sites. Everything went smoothly except for this error:

Warning: date(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected the timezone 'UTC' for now, but please set date.timezone to select your timezone. in /home/administratorhc/public_html/CMS/images/installed.png on line 2

site: heritagecircle.org

heritagecircle.org/index-hold.php

I can, of course, turn off error reporting for this but would rather find and nuke the error, can you assist?

also getting this error in heritagecircle.org/CMS:
Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/administratorhc/public_html/CMS/images/installed.png:2) in /home/administratorhc/public_html/CMS/WA_SecurityAssist/Helper_PHP.php on line 5

Warning: Cannot modify header information - headers already sent by (output started at /home/administratorhc/public_html/CMS/images/installed.png:2) in /home/administratorhc/public_html/CMS/admin_cms/users_login.php on line 45

Warning: Cannot modify header information - headers already sent by (output started at /home/administratorhc/public_html/CMS/images/installed.png:2) in /home/administratorhc/public_html/CMS/admin_cms/users_login.php on line 48

All of the other errors are as a result of the first.

The best solution is to set the default timezone in the php.ini file by setting the value for date.timezone. This can usually be done in your server's admin control panel.

i could not find it in the admin panel so I added
date.timezone = "US/Mountain"
manually to the php.ini file and EVERYTHING is groovy. All errors resolved.

Again, as always, thanks for your help -- YOU ARE A GENIUS!!!!