         components.hour = 0
         components.minute = 0
         components.second = 0
-        return Calendar(identifier: .gregorian).date(from: components)!
+        return Calendar.gregorianGMT.date(from: components)!
     }
     
     public var fractionalYear: Double {

     - returns: The value of the Julian Day, as a fractional (double) number.
     */
    public func julianDay() -> JulianDay {
        let calendar = Calendar(identifier: .gregorian)
        let components = calendar.dateComponents([.year, .month, .day, .hour, .minute, .second, .nanosecond], from: self)
        
        let year = Double(components.year!)

        components.second = Int(floor(second))
        components.nanosecond = Int((second-floor(second))*1e6)
        
        var calendar = Calendar.gregorianGMT
        return calendar.date(from: components)!
    }
    
