How to patch Date/time type field with time zone by formula language in Lotus notes

Question

I have a date/Time field in my LN doc. The date stored as "11/09/2014 11:04:25 ZE4". I want to patch the same with 11/09/2013 11:04:25 ZE8. How to do it through formula language ??

Answer 1

text := @LeftBack(@Text(myDateField; "D0T0Z2"); " ");
date := @TextToTime(@Left(text; " "));
time := @TextToTime(@Right(text; " "));
result := @TimeMerge(date; time; "Z=-8");

Answer 2

FIELD whatever := @ToTime("4/15/2020 5:46:13 AM ZE8");