Change Data and time Irrespective of Users Time zone

Let me look up the function for you ...

https://docs.appian.com/suite/help/25.3/fnc_date_and_time_gmt.html

Working example

a!localVariables(
  local!now:now(),
text(
  local(
    gmt(now()),
    "CST"
  ),
  "MM/dd/yyyy hh:mm a"
)
)

I'll jump in here and - affirming Shubham's suggested recipe as the likely solution - you will find this a lot less confusing to deal with if you abstract all such functionality behind an Expression Rule (or perhaps a small handful of different rules to handle different related pieces of this functionality) - as this will make it quite a bit easier to test out and keep up with as your system expands, and you're faced with potential future requirement shifts / additions.