I took a look at this...
I ran /opt/observium/poller.php -d and saw this:
##### Timezones info #####
o Date Tuesday, 10-Dec-19 21:08:21 EST
o PHP -05:00
o MySQL -05:00
This looks like it's correct and PHP and MySQL have matching time offset.
root@c3b53bf2ea0d:/opt/observium# mysql -u observium -p observium
Enter password:
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 16
Server version: 10.4.8-MariaDB-1:10.4.8+maria~bionic-log mariadb.org binary distribution
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [observium]> select now();
+---------------------+
| now() |
+---------------------+
| 2019-12-10 21:11:56 |
+---------------------+
1 row in set (0.000 sec)
MariaDB [observium]>
This is also showing the correct time.
I even tried adding "default-time-zone='-05:00'" to "/etc/mysql/my.cnf" and restarting the database and that didn't make any difference. The graphs are still in UTC.
I'm not sure what's the problem at this point.