/// <summary>
/// Get a DateTime representing the current unit of time.
/// </summary>
/// <param name="current">The current date.</param>
/// <param name="dateUnit">The date unit.</param>
/// <returns></returns>
public static DateTime This(this DateTime current, DateUnit dateUnit)
{
switch (dateUnit)
{
case DateUnit.Day:
return current.Midnight();
case DateUnit.Week:
return current.AddWeeks(-1).Next(CultureInfo.CurrentCulture.DateTimeFormat.FirstDayOfWeek);
case DateUnit.Month:
return current.First();
case DateUnit.Year:
return new DateTime(current.Year,1,1);
}
return current;
}
/// <summary>
/// Adds one week to the specified <see cref="DateTime">DateTime</see> value.
/// </summary>
/// <param name="value">The date to evaluate.</param>
/// <returns>A <see cref="DateTime">DateTime</see> representing one weeek after the specified <see cref="DateTime">DateTime</see>.</returns>
public static DateTime AddWeek(this DateTime value)
{
return value.AddWeeks(1);
}
/// <summary>
/// Subtracts given weeks from the given DateTime.
/// </summary>
/// <param name="date">The given DateTime.</param>
/// <param name="weeks">Number of weeks to be subtracted.</param>
/// <returns>The DateTime after the given weeks are subtracted.</returns>
public static DateTime SubtractWeeks(this DateTime date, int weeks)
{
return date.AddWeeks(weeks.Negate());
}
/// <summary>
/// Adds one week to the given DateTime.
/// </summary>
/// <param name="date">The given DateTime.</param>
/// <returns>The DateTime after one week is added.</returns>
public static DateTime AddAWeek(this DateTime date)
{
return date.AddWeeks(1);
}
public static DateTime SubtractWeeks(this DateTime dateTime, int weeks)
{
return dateTime.AddWeeks(-weeks);
}
public static DateTime SubtractWeeks(this DateTime date, double value) {
if (value < 0)
throw new ArgumentException("Value cannot be less than 0.", "value");
return date.AddWeeks(value * -1);
}
public static DateTime AddWeek(this DateTime d)
{
return d.AddWeeks(1);
}
public static DateTimeOffset SubtractWeeks(this DateTimeOffset dateTimeOffset, double weeks)
{
return dateTimeOffset.AddWeeks(-weeks);
}
public static DateTime? GetDayOfWeekInTheMonth(this DateTime date, DayOfWeek dayOfWeek, int instance)
{
if (instance <= 0)
return null;
date = FirstDayOfTheMonth(date, dayOfWeek);
if (instance == 1)
return date;
return date.AddWeeks();
}