Flutter/Dart: Split string by first occurrence

You were never going to be able to do all of that, including trimming whitespace, with the split command. You will have to do it yourself. Here’s one way:

String s = "date   :   '2019:04:01'";
int idx = s.indexOf(":");
List parts = [s.substring(0,idx).trim(), s.substring(idx+1).trim()];