convert from TimeInterval to String with func and parameter on output

Question

I can't convert from TimeInterval to String with func and parameter on output.

It gives me this error message: Cannot convert value of type 'TimeInterval' (aka 'Double') to expected argument type 'Date'

import Foundation

extension Date {

func timeIntervalToString(date: TimeInterval) -> String {
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
        let dateString = dateFormatter.string(from: date)
        return dateString
    }

}

Answer 1

DateFormatter.string(from:) receives a Date as an input parameter not a TimeInterval.

Your TimeInterval needs to be in a form like 1716889787. It represents the number of seconds since 01/01/1970.

I believe it should be:

func timeIntervalToString(date: TimeInterval) -> String {
    let date = Date(timeIntervalSince1970: date) //<- here
    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
    let dateString = dateFormatter.string(from: date)
    return dateString
}