/// <summary>
/// Subtracts given decades from the given DateTime.
/// </summary>
/// <param name="date">The given DateTime.</param>
/// <param name="decades">Number of decades to be subtracted.</param>
/// <returns>The DateTime after the given decades are subtracted.</returns>
public static DateTime SubtractDecades(this DateTime date, int decades)
{
return(date.AddDecades(decades.Negate()));
}
/// <summary>
/// Adds one decade to the given DateTime.
/// </summary>
/// <param name="date">The given DateTime.</param>
/// <returns>The DateTime after one decade is added.</returns>
public static DateTime AddADecade(this DateTime date)
{
return(date.AddDecades(1));
}