Flutter gave us the easiest way to convert it.
You just need to pass utc: true while parsing your date.
var dateTime = DateFormat("yyyy-MM-dd HH:mm:ss").parse(dateUtc, true);
var dateLocal = dateTime.toLocal();
Input:
Assume my TimeZone : +05:30
UTC Date -> 2020-02-12 23:57:02.000
Output:
Local Date -> 2020-02-12 18:27:02.019660