SQL variables for datetime field

[pvanthony]

My bad for the redact.

You are correct I do not need the time. Is just that the database field is datatime and requires the time.

1. The database is postgresql 9.6 and the database field is datetime.

2. Here is the full sql.
   
SELECT res_partner_category.name, SUM(account_invoice_line.quantity)
FROM res_partner
INNER JOIN account_invoice_line ON account_invoice_line.partner_id = res_partner.id
INNER JOIN res_partner_res_partner_category_rel ON res_partner.id = res_partner_res_partner_category_rel.partner_id
INNER JOIN res_partner_category ON res_partner_category.id = res_partner_res_partner_category_rel.category_id
WHERE
account_invoice_line.booking_start > '{{start_year}}-{{start_month}}-{{start_day}} 23:59'
AND account_invoice_line.booking_end < '{{end_year}}-{{end_month}}-{{end_day}} 00:00'
AND account_invoice_line.company_id = 3
GROUP BY res_partner_category.name


3. Here is the screenshot.
   

   

Am I going about this the wrong way? Should I just use the gui based query instead of the sql way?
I am not so familiar with the gui based query.

Thank you again for continuing to help. I do appreciate it.