Hi Sudiptab,
maybe you can use functions docs.appian.com/.../fnc_date_and_time_datetime.html and docs.appian.com/.../fnc_scripting_datetext.html
Example : datetext(datetime(1970, 01, 01, 0, 0, 0) + 1534147522/86400,"yyyy-MM-dd'T'HH:mm:ss")
Test Output…