Parse ISO8601 like datetime string [Arduino]

StringToDateTime.ino

// Data string
String time_string = "2021-12-12 18:55:54";

// Parsing
int year = time_string.substring(0, 4).toInt();
int month = time_string.substring(5, 7).toInt();
int day = time_string.substring(8, 10).toInt();
int hour = time_string.substring(11, 13).toInt();
int minute = time_string.substring(14, 16).toInt();
int second = time_string.substring(17, 19).toInt();

// Creating DateTime object
DateTime new_time = DateTime(year, month, day, hour, minute, second);