Some applications require date.timezone variable to be set in "php.ini" file. To set, do the following.

Update files

Depending on your system setup, there may be three "ini" files. Assign a timezone e.g. "Europe/London" to date.timezone variable in each "ini" files, save and exit.

sudo nano /etc/php5/apache2/php.ini
sudo nano /etc/php5/cli/php.ini
sudo nano /etc/php5/fpm/php.ini

; Defines the default timezone used by the date functions
date.timezone = Europe/London