Swift: Convert Dates to elapsed and remaining time string – Ios swift

I have a Current, Start Date, and End Date. How can I convert these dates to elapsed and remaining time format using Swift?

The format needed is 00:00:00 (hours: minutes: seconds)

Currently, I get elapsed and remaining strings using the below code.

The code returns incorrectly to the Time I see in the Simulator.

Example: If the simulator time changes to 2:45 pm
My elapsed time’s second is ahead (10s) of the actual seconds shown.
And the remaining seconds shows ahead for (9s)

I am getting like this

elapsed = 01:30:10, rem = 12:30:09

Can you help me fix the code or a simpler way to get the format I want correctly?

Code:

{
    let currDate = Date();

    let startDate = currDate;
    let endDate: Date = startDate.addingTimeInterval(TimeInterval(minutes * 60));

    Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(callback),  userInfo: nil, repeats: true);

}

@objc func Callback() {

    let time = dateToTimerString(currDate: currDate, startDate: startDate, endDate: endDate );
    NSLog( "Elapsed %@, Rem %@", time.elapsed, time.remaining );
}

func dateToTimerString(currDate: Date, startDate: Date, endDate: Date) -> (elapsed: String, remaining: String) {
    
    let elapsedTime: TimeInterval = currDate.timeIntervalSince(startDate);
    let remainingTime: TimeInterval = endDate.timeIntervalSince(currDate);
    
    let elapsedString = format(duration: elapsedTime);
    let remainingString = format(duration: remainingTime);
    
    return (elapsedString, remainingString);
}

func format(duration: TimeInterval) -> String {
    let formatter = DateComponentsFormatter()
    formatter.allowedUnits = [.hour, .minute, .second]
    formatter.unitsStyle = .positional
    formatter.zeroFormattingBehavior = .pad

    return formatter.string(from: duration)!
}