The database is correct in this case. comment_date
is the datetime of your WordPress timezone setting and comment_date_gmt
is the same datetime, but converted to Greenwich Mean Time (GMT). GMT is the timezone all other timezones are offset from while UTC is the time standard. In most practical applications they’re interchangeable.
The problem you’re probably having is either saving or reading the datetime converted to your local timezone from either GMT or your site’s set timezone.