This issue is not very serious because if you clean the Build folder it compiles, BUT it bugs me. Description: I have a simple APP that runs on iPhone and on my MAC (M2) where I develop; sometimes (and I cannot say what triggers it) when hitting the "start the active scheme" arrow, it runs the old build without compiling even if I have made some changes. If you explicitly save the file modified it still does not compile, the only way you can get to "refresh" is by cleaning the Build folder. After many years developing with SWIFT and all the bugs we helped remove, I still concur with the other guys saying SWIFT is not a mature language/compiler/IDE.

The following code:  let start_time = (NSDate().timeIntervalSince1970) let GET_start_acq_time = NSDate(timeIntervalSince1970: Double(start_time)) let formatter = DateFormatter() formatter.locale = NSLocale.current formatter.dateFormat = "YYYY-MM-DD HH:mm:ss:SSS" let GET_start_acq_time_string = formatter.string(from: GET_start_acq_time as Date) print("Today's date = (GET_start_acq_time_string)") output this date Today: Today's date = 2023-02-32 10:26:39:965 Yesterday was fine. Have fun with it, it is simple to reproduce, it's on IOS latest Xcode