MongoDB.Bson.BsonUtils.ToDateTimeFromMillisecondsSinceEpoch C# (CSharp) Method

        public static DateTime ToDateTimeFromMillisecondsSinceEpoch(long millisecondsSinceEpoch)
        {
            if (millisecondsSinceEpoch < BsonConstants.DateTimeMinValueMillisecondsSinceEpoch ||
                millisecondsSinceEpoch > BsonConstants.DateTimeMaxValueMillisecondsSinceEpoch)
            {
                var message = string.Format(
                    "The value {0} for the BsonDateTime MillisecondsSinceEpoch is outside the"+
                    "range that can be converted to a .NET DateTime.",
                    millisecondsSinceEpoch);
                throw new ArgumentOutOfRangeException("millisecondsSinceEpoch", message);
            }

            // MaxValue has to be handled specially to avoid rounding errors
            if (millisecondsSinceEpoch == BsonConstants.DateTimeMaxValueMillisecondsSinceEpoch)
            {
                return DateTime.SpecifyKind(DateTime.MaxValue, DateTimeKind.Utc);
            }
            else
            {
                return BsonConstants.UnixEpoch.AddTicks(millisecondsSinceEpoch * 10000);
            }
        }

 /// <summary>
 /// Initializes a new instance of the BsonDateTime class.
 /// </summary>
 /// <param name="millisecondsSinceEpoch">Milliseconds since Unix Epoch.</param>
 public BsonDateTime(long millisecondsSinceEpoch)
     : base(BsonType.DateTime)
 {
     this.millisecondsSinceEpoch = millisecondsSinceEpoch;
     if (millisecondsSinceEpoch >= BsonConstants.DateTimeMinValueMillisecondsSinceEpoch &&
         millisecondsSinceEpoch <= BsonConstants.DateTimeMaxValueMillisecondsSinceEpoch)
     {
         this.value = BsonUtils.ToDateTimeFromMillisecondsSinceEpoch(millisecondsSinceEpoch);
     }
 }