{% macro convert_timezone(value, format, timezone) %}
    {% if timezone | length %}
        {% set expression %}
            cast (FROM_TZ(to_timestamp('{{ value }}', '{{ format }}'), '{{ timezone }}') at time zone '{{ var("dbt_timezone") }}' as timestamp)
        {% endset %}
    {% else %}
        {% set expression %}
            to_timestamp('{{ value }}', '{{ format }}')
        {% endset %}        
    {% endif %}
    {{ return(expression) }}
{% endmacro %}