I am facing some strange issue, I believe its due to my ignorant, would appreciate if you can help me out on this:

DB Server system OS CentOS.

I have loaded the timezone tables in mysql using:

mysql_tzinfo_to_sql /usr/share/zoneinfo | mysql -u root -p mysql

After loading, I have restrated the DB using systemctl restart mariadb:

Then I have tried below in DB:

select @@global.time_zone,@@system_time_zone;

SELECT CONVERT_TZ( NOW(), @@global.time_zone , 'UTC' ), UTC_TIMESTAMP;

SELECT CONVERT_TZ( NOW(), @@system_time_zone , 'UTC' ), UTC_TIMESTAMP;

SELECT CONVERT_TZ( NOW(), 'EDT' , 'UTC' ), UTC_TIMESTAMP;

For some reason, If I use named TZ in CONVERT_TZ function for FROM_TZ, its always showing NULL. 

Can anyone help me out what else i can do so I can pass the abbreviation or named TZ in FROM_TZ. 

Regards,

Karthick