How can I create datetime in particular time zone in Appian ?

My Appian Timezone is set to Pacific time

Below functions are returning correct time

now()  -   2/20/2023 5:40 AM PST

datetime(year(now()),month(now()),day(now()),hour(now()),minute(now()))   -  2/20/2023 5:40 AM PST

However, when I try to create datetime where I want to change the date and time acc to my preference, the timezone offset gets added. 

datetime(year(now()),month(now()),day(now()),0,0) – 2/19/2023 4:00 PM PST  

I want the output as - 2/20/2023 12:00 AM PST

Requirement for which I want to create datetime in specific timezone.

Now I want to create a datetime so that I can use it to filter the datetime column stored in DB

I need to fetch all rows from DB where the createdDate is say 2/20/2023 so for that I thought of creating a query filter as

Date between (2/20/2023 12:0AM PST and 2/20/2023 11:59 PM PST).

However I am unable to create datetime in particular time zone