How to change database timezone from UTC to local in wordpress

I'm using a custom plugin in wordpress. All date and time are stored in database as UTC. I saw in posts table, there're 2 columns for UTC and local timezone (post_date, post_date_gtm), but in this plugin table, there's only 1 column to store the created date as UTC.

Currently, I'm using sql query and $wpdb to show the data between "start date" and "end date". Please help me to show them in local timezone (That is setted in general setting) instead of UTC!

Thanks and sorry about my English.

via Chebli Mohamed