Convert DateTime.Now to an ever-decreasing Ticks String to be used as Keys in Azure Table Storage

TableStorageKeys.cs

  /// <summary>
  /// Returns an ever-decreasing number as string to be used as PartitionKey or RowKey.
  /// Ensures that newly created entities are always "on top" and returned first in queries
  /// </summary>
  /// <returns></returns>
  public static string TicksKey()
  {
      return (DateTime.MaxValue.Ticks - DateTime.UtcNow.Ticks).ToString("d19");
  }

  /// <summary>
  /// Converts TicksKey back to DateTimeOffset
  /// </summary>
  /// <param name="ticksKey"></param>
  /// <returns></returns>
  public static DateTimeOffset TicksKeyToDateTimeOffset(string ticksKey)
  {
     return new DateTimeOffset(DateTime.MaxValue.Ticks - long.Parse(ticksKey), TimeSpan.Zero);
  }