Getting system uptime in iOS/Swift

Question

Is there a way to get system uptime in iOS (using Swift)? What I need is to measure time without having to worry about the user changing the time. In Android there\'s a

Answer 1

Updated for Swift 5 and straight from ADF post here:

func bootTime() -> Date? {  
    var tv = timeval()  
    var tvSize = MemoryLayout.size  
    let err = sysctlbyname("kern.boottime", &tv, &tvSize, nil, 0);  
    guard err == 0, tvSize == MemoryLayout.size else {  
        return nil  
    }  
    return Date(timeIntervalSince1970: Double(tv.tv_sec) + Double(tv.tv_usec) / 1_000_000.0)  
}

"Be aware that this time will change if the system clock changes, that is, the value is the boot time relative to the current system clock."