Contribution widget requires time zone to be set in Date.php (or at least someplace not set in a new install)
On a new Drupal install of CiviCRM 5.5.1 could not get contribution widget to work. It required adding a line to Date.php at /public_html/sites/all/modules/civicrm/CRM/Utils/Date.php (used
date_default_timezone_set("America/Chicago"); at top of file). This would get overwritten if update CiviCRM, so not a good solution!
php.ini already showing timezone set:
**date** date/time support enabled "Olson" Timezone Database Version 2016.10 Timezone Database internal Default timezone America/Chicago Directive Local Value Master Value date.default_latitude 31.7667 31.7667 date.default_longitude 35.2333 35.2333 date.sunrise_zenith 90.583333 90.583333 date.sunset_zenith 90.583333 90.583333 date.timezone America/Chicago no value
and Drupal also set in the same way at /admin/config/regional/settings
Also, as stated in issue 20, can't put Contribution Widget on the contribution page itself, and putting the progress thermometer on this page is a common need. (Work-around I used was a Drupal block with a special version suppressing display in CSS of the description, etc., so not totally redundant.)