public startTime: string;

public setDate(date: string) {
    let date:Date = new Date(date);
    this.startTime = date.getHours() + ':';
    if (date.getMinutes() < 10) {
        this.startTime += date.getMinutes() + '0';
    } else {
        this.startTime += date.getMinues();
    }
 }

it('should pass') {
    let testDate = new customDate();
    testDate.setDate('2017-07-20T14:20');
    expect(testDate.startTime).toBe('14:00'); <-- this is failing it's comeing through as ('8:00')
}