function DateTime(ctx) {
      _classCallCheck(this, DateTime);
      this.ctx = ctx;
      this.w = ctx.w;
      this.months31 = [1, 3, 5, 7, 8, 10, 12];
      this.months30 = [2, 4, 6, 9, 11];
      this.daysCntOfYear = [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334];
    }
DateTime Class to manipulate datetime values.

@module DateTime