Blog Post by Murat Yaşar

1. Blog
2. Calculate Time Difference Between Two Dates Excluding Weekend and Special Holidays
3. Technical

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Posted on Monday, March 07, 2022 2:58:58 PM and it has been read 2093 times since then.

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Calculate Time Difference Between Two Dates Excluding Weekend and Special Holidays

Hello, it's been quite some time since I last wrote on my blog.

This one also will be a short one, not long.

I needed a method that calculates the time difference between two dates. Also, I needed to exclude weekends and special holidays from the calculation.

Maybe it will help someone, at least as a starting point.

As you can see the method takes a parameter named holidays. This parameter is the list of special holidays.

Data is read from database and sent to this method as dto object. Below I will show both the table and the dto object scripts.

CREATE TABLE [dbo].[SpecialHolidays](
	[Id] [bigint] IDENTITY(1,1) NOT NULL,
	[SpecialHoliday] [datetime2](7) NOT NULL,
	[AllDay] [bit] NOT NULL,
	[IsActive] [bit] NOT NULL,
	[DateCreated] [datetime2](7) NOT NULL,
 CONSTRAINT [PK_SpecialHolidays] PRIMARY KEY CLUSTERED 
(
	[Id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO

ALTER TABLE [dbo].[SpecialHolidays] ADD  CONSTRAINT [DF_SpecialHolidays_AllDay]  DEFAULT ((1)) FOR [AllDay]
GO

ALTER TABLE [dbo].[SpecialHolidays] ADD  CONSTRAINT [DF_SpecialHolidays_IsActive]  DEFAULT ((1)) FOR [IsActive]
GO

ALTER TABLE [dbo].[SpecialHolidays] ADD  CONSTRAINT [DF_SpecialHolidays_DateCreated]  DEFAULT (getdate()) FOR [DateCreated]
GO

EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'We write 1 if it is a full day''s holiday and 0 if it is a half-day holiday.' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'SpecialHolidays', @level2type=N'COLUMN',@level2name=N'AllDay'
GO

public class SpecialHolidaysDto
{
    public DateTime SpecialHoliday { get; set; }
    public bool? AllDay { get; set; }
}

You can see a sample code block below.

private static double CalculateInHours(DateTime startDate, DateTime endDate, 
                                       List<SpecialHolidaysDto> holidays)
{
	TimeSpan interval = new TimeSpan();

	DateTime savedDateForHoliday = new DateTime(startDate.Year, startDate.Month, 
                                                startDate.Day, startDate.Hour, 
                                                startDate.Minute, startDate.Second);

	bool firstIteration = true;
	
	for (DateTime dateValue=startDate;dateValue<=endDate;dateValue=dateValue.AddHours(1))
	{
		if (dateValue.DayOfWeek==DayOfWeek.Saturday || dateValue.DayOfWeek==DayOfWeek.Sunday)
		{
			dateValue = Convert.ToDateTime((dateValue.AddDays(1)).ToString("yyyy-MM-dd"));

			continue;
		}

		if (firstIteration == true || savedDateForHoliday.Date != dateValue.Date)
		{
			savedDateForHoliday = dateValue;

			firstIteration = false;

			var specialholidayvalue = holidays
                                      .Select(x => new { 
                                                        date = x.SpecialHoliday, 
                                                        isalldaylong = x.AllDay })
                                      .Where(y => y.date == dateValue.Date).FirstOrDefault();

			if (specialholidayvalue != null)

				savedDateForHoliday = specialholidayvalue.date;


			if (specialholidayvalue!=null && dateValue.Date==specialholidayvalue.date.Date)
			{
				if (specialholidayvalue.isalldaylong == false)
				{
					interval += TimeSpan.FromHours(4.5);
				}

				dateValue = Convert.ToDateTime((dateValue.AddDays(1)).ToString("yyyy-MM-dd"));

				continue;
			}
		}

		interval += TimeSpan.FromHours(1);
	}
	
	return interval.TotalHours;
}

Have a great day.

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