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How to compare just month and day from a datetime object

In my C# program I have run into an obstacle where I have a table that stores date ranges (columns are date range ID (int), begin date (DateTime) and end date (DateTime). I want to query the table and get back rows that only fall within a specific date range. I cannot use datetime.date since that includes the year.
So for example, I want to query the table and get all date ranges that fall between 01-01 and 5-31.
I have tried using the following lambda to query the table, but my result set is empty.
List<DateRanges> tempDateRangeList = dataContext
.DateRanges
.Where(r=>r.BeginDate.Month <= startDate.Month
&& r.EndDate.Month >= finishDate.Month)
.ToList();
tempDateRangeList = tempDateRangeList.Where(r=>r.BeginDate.Day <= startDate.Day
&& r.EndDate.Day >= finishDate.Day)
.ToList();
Does anyone have any suggestions on how I could accomplish this?
Edit:
Examples of BeginDate and EndDate would be a list such as follows:
BeginDate 1/1/2016, 5/25/2016, 9/11/2016
EndDates 5/24/2016, 9/10/2016, 12/31/2016
Filter date would be:
startDate = 12/8
finishDate = 12/12
Expected result:
Begin Date of 9/11
End date of 12/31

There are two cases in your condition - month equal to boundary month, in which case you must test day number, and a different month, in which you ignore day. Hence the query:
List<DateRanges> tempDateRangeList =
dataContext.DateRanges.Where(r =>
((r.BeginDate.Month < startDate.Month) ||
(r.BeginDate.Month == startDate.Month && r.BeginDate.Day <= startDate.Day)) &&
((r.EndDate.Month > finishDate.Month) ||
(r.EndDate.Month == finishDate.Month) && r.EndDate.Day >= finsihDate.Day))
.ToList();
Condition is ugly and very hard to follow but covers all cases. This query returns all records which define date ranges that completely fall under the boundary dates.
If you wish to find records that are just overlapping (completely or partially) with the filtering range, then the query would be:
List<DateRanges> tempDateRangeList =
dataContext.DateRanges.Where(r =>
((r.BeginDate.Month < endDate.Month) ||
(r.BeginDate.Month == endDate.Month && r.BeginDate.Day <= endDate.Day)) &&
((r.EndDate.Month > startDate.Month) ||
(r.EndDate.Month == startDate.Month) && r.EndDate.Day >= startDate.Day))
.ToList();
This condition may bend your mind, but it works fine.

If a lambda expression isn't compulsory, I've used linq queries (because it was the first solution i've thought).
var validRanges = from range in ranges
where range.BeginDate.CompareTo(startDate) <= 0
where range.EndDate.CompareTo(endDate) >= 0
select range;
Using CompareTo is the easiest way to compare two DateTime struct.
I invite you to take a look here for a complete description of the method.
Edit
If you aren't interested in hours of your dates, but only in Day and Month, you should use range.BeginDate.Date.CompareTo(startDate.Date) and range.EndDate.Date.CompareTo(endDate.Date)

Comparing times without date?

I am having trouble comparing times.
From what I have researched it most likely is due to the time not having a date.
My code,
This gets a dateTime value from the database.
var getDateTime = sql.Staff_Time_TBLs.Where(p => p.Staff_No ==
SelectedEmployee.Key && p.Date_Data == day).Select(p => p.Time_Data_1).ToList();
DateTime dateTimeGet = Convert.ToDateTime(getDateTime);
dateTimeGet returns a value like this "2012/12/12 15:03:00.000"
I then declare variables to hold the time.
TimeSpan startCompare = TimeSpan.Parse("15:00");
TimeSpan endCompare = TimeSpan.Parse("21:00");
Then comparing the values Compare DateTime
if ((endCompare > dateTimeGet) && (startCompare < dateTimeGet))
{
//match found
}
I am getting a compile error,
operands cannot be given to to type timespan and datetime
How do I compare times in this situation?

Just edit your code like this:
if ((endCompare > dateTimeGet.TimeOfDay) && (startCompare < dateTimeGet.TimeOfDay))
{
//match found
}

You could create DateTime values instead of TimeSpan to compare the value, using the Date of your db time:
DateTime startCompare = dateTimeGet.Date.AddHours(15);
DateTime endCompare = dateTimeGet.Date.AddHours(21);
if ((endCompare > dateTimeGet) && (startCompare < dateTimeGet))
{
// match found
}
In the example you showed, actually would be enough to compare the Hour part of dateTimeGet:
if (dateTimeGet.Hour >= 15 && dateTimeGet.Hour <= 21)
// match found

Actually you are comparing time with date in endCompare > dateTimeGet so you are getting the error
operands cannot be given to to type timespan and datetime
To compare time-span you need to extract the time from date in dateTimeGet by simply using TimeOfDay.
if ((endCompare > dateTimeGet.TimeOfDay) && (startCompare < dateTimeGet.TimeOfDay))
{
//match found
}
This will convert the date into time. For more details about TimeOfDayclick here Hope this works fine for you.

The issue is that, as you rightly say, you are comparing dates to times
A time-span is a measurement of time measured in Hours, where as a date-time is a measurement of time measured in days
so 2012/12/12 15:03:00.000 is approximately 735248.625 days or 17645967 hours
which you are then comparing to a timespan of 15 hours
so you need to either add 735248 days to your time span or drop 735248 days form your Date
both can be easily done
If you call the time TimeOfDay property on the date it will ignore the days and just return 0.625 days as 15 hours
Which means your code would look like this
if ((endCompare > dateTimeGet.TimeOfDay ) && (startCompare < dateTimeGet.TimeOfDay))
OR
If you add the time span to the at midnight date it will create the correct date time for comparation
Which means your code would look like this
if ((dateTimeGet.Date + endCompare > dateTimeGet ) && (dateTimeGet.Date + startCompare < dateTimeGet.TimeOfDay))

LINQ filter nullable datetime with matching params?

I need to filter my nullable datetime by day month and year.
I currently trying to do it by using string comparisons. I have this in where statement in linq:
DOB.ToString().StartsWith("2/25/19") || DOB == null
But its not working. I know its because the server doesnt store the date like that, but Im unsure as to how it is storing it, and how can I retrieve it and do the comparison.
I REALLY need this to happen on the database. I cant get everything and filter in the server.
I just want linq to filter dates by day, month, and year
Any help or pointers are appreciated.

You could try something like this (updated to include optional date components):
int? month = 2;
int? day = 25;
int? century = 19; // actual century minus one
// other LINQ here
.Where(x => x.DOB == null
|| ((month == null || x.DOB.Month = month)
&& (day == null || x.DOB.Day = day)
&& (century == null || x.DOB.Year / 100 == century)));

try this:
context.Entities.Where(e => e.Date != null && e.Date.Day == 15)
you can use DateTime.Day, DateTime.Month, DateTime.Year and the logical operators && and || to filter as you see fit. You must however check for nullity first or you may end up with NullExceptions

If you want to filter by day, month, year, use the example code below:
DateTime dateTime = DateTime.Now;
Console.WriteLine(dateTime.Day);
Console.WriteLine(dateTime.Month);
Console.WriteLine(dateTime.Year);
You can get those value from DateTime object. Then, you can apply filter on it.
After reading the comment, I got your point.
For example, you enter a string like this:
string search = "2/25/2015";
Now, you want to extract the value of the string to perform filter, right? Simply do:
string[] values = search.Split('/');
Then, the values would be [2, 25, 2015]. First element is month, second is day, third is year, that depends on how you define the format.

Comparing dates in linq

I would like to query the db for items with a date greater than or equal to a given date.
The date in the db is a datetime and records time.
If the user enters the search string "1/30/2014", they expect entries that occurred at any time on that date to be returned. However, anything that has a time after 12 am is not returned.
I know I could simply add a day to the search string, but is there a more appropriate way?
if (form["closedend"] != "")
{
DateTime d = DateTime.Parse(form["closedend"]);
traces = traces.Where(s => s.date_Closed >= d);
}

You can use the Date property to truncate the time part:
traces = traces.Where(s => s.date_Closed.Date <= d.Date);
On this way you'd include this day since both DateTimes are midnight.
Update if you use LINQ to Entities DateTime.Date is not supported, you could use this solution: Using DateTime in LINQ to Entities
.Where(s => EntityFunctions.TruncateTime(s.date_Closed) <= EntityFunctions.TruncateTime(d))

You said
with a date greater than or equal to a given date
but in your code you write
s.date_Closed <= d
I think you must change <= by >= to obtain dates greater or equal to d, now you're getting dates less or equal to d.

For this example you don't need neccessary any other dll. You can implement other function, which return bool, f.e:
public bool MyFunction(DateTime s)
{
DateTime d = DateTime.Parse(Your constructor);
return (s.date_Closed >= d);
}
var query = from obj in traces
where MyFunction(obj.date_Closed.Date)
select obj;
or:
var query = traces.Where(p => MyFunction(p.data_Closed.Date));

You can use DbFunctions.TruncateTime(StartDateTime) To remove the time from datetime.
if (form["closedend"] != "")
{
DateTime d = DateTime.Parse(form["closedend"]);
traces = traces.Where(s => DbFunctions.TruncateTime(s.date_Closed) >= DbFunctions.TruncateTime(d));
}

How to compare only Date without Time in DateTime types in Linq to SQL with Entity Framework?

Is there a way to compare two DateTime variables in Linq2Sql but to disregard the Time part.
The app stores items in the DB and adds a published date. I want to keep the exact time but still be able to pull by the date itself.
I want to compare 12/3/89 12:43:34 and 12/3/89 11:22:12 and have it disregard the actual time of day so both of these are considered the same.
I guess I can set all the times of day to 00:00:00 before I compare but I actually do want to know the time of day I just also want to be able to compare by date only.
I found some code that has the same issue and they compare the year, month and day separately. Is there a better way to do this?

try using the Date property on the DateTime Object...
if(dtOne.Date == dtTwo.Date)
....

For a true comparison, you can use:
dateTime1.Date.CompareTo(dateTime2.Date);

This is how I do this in order to work with LINQ.
DateTime date_time_to_compare = DateTime.Now;
//Compare only date parts
context.YourObject.FirstOrDefault(r =>
EntityFunctions.TruncateTime(r.date) == EntityFunctions.TruncateTime(date_to_compare));
If you only use dtOne.Date == dtTwo.Date it wont work with LINQ (Error: The specified type member 'Date' is not supported in LINQ to Entities)

If you're using Entity Framework < v6.0, then use EntityFunctions.TruncateTime
If you're using Entity Framework >= v6.0, then use DbFunctions.TruncateTime
Use either (based on your EF version) around any DateTime class property you want to use inside your Linq query
Example
var list = db.Cars.Where(c=> DbFunctions.TruncateTime(c.CreatedDate)
>= DbFunctions.TruncateTime(DateTime.UtcNow));

DateTime dt1 = DateTime.Now.Date;
DateTime dt2 = Convert.ToDateTime(TextBox4.Text.Trim()).Date;
if (dt1 >= dt2)
{
MessageBox.Show("Valid Date");
}
else
{
MessageBox.Show("Invalid Date... Please Give Correct Date....");
}

DateTime? NextChoiceDate = new DateTime();
DateTIme? NextSwitchDate = new DateTime();
if(NextChoiceDate.Value.Date == NextSwitchDate.Value.Date)
{
Console.WriteLine("Equal");
}
You can use this if you are using nullable DateFields.

DateTime dt1=DateTime.ParseExact(date1,"dd-MM-yyyy",null);
DateTime dt2=DateTime.ParseExact(date2,"dd-MM-yyyy",null);
int cmp=dt1.CompareTo(dt2);
if(cmp>0) {
// date1 is greater means date1 is comes after date2
} else if(cmp<0) {
// date2 is greater means date1 is comes after date1
} else {
// date1 is same as date2
}

DateTime econvertedDate = Convert.ToDateTime(end_date);
DateTime sconvertedDate = Convert.ToDateTime(start_date);
TimeSpan age = econvertedDate.Subtract(sconvertedDate);
Int32 diff = Convert.ToInt32(age.TotalDays);
The diff value represents the number of days for the age. If the value is negative the start date falls after the end date. This is a good check.

In .NET 5:
To compare date without time you must use EF.Functions.DateDiffDay() otherwise you will be comparing in code and this means you are probably pulling way more data from the DB than you need to.
.Where(x => EF.Functions.DateDiffDay(x.ReceiptDate, value) == 0);

You can try
if(dtOne.Year == dtTwo.Year && dtOne.Month == dtTwo.Month && dtOne.Day == dtTwo.Day)
....

In your join or where clause, use the Date property of the column. Behind the scenes, this executes a CONVERT(DATE, <expression>) operation. This should allow you to compare dates without the time.

int o1 = date1.IndexOf("-");
int o2 = date1.IndexOf("-",o1 + 1);
string str11 = date1.Substring(0,o1);
string str12 = date1.Substring(o1 + 1, o2 - o1 - 1);
string str13 = date1.Substring(o2 + 1);
int o21 = date2.IndexOf("-");
int o22 = date2.IndexOf("-", o1 + 1);
string str21 = date2.Substring(0, o1);
string str22 = date2.Substring(o1 + 1, o2 - o1 - 1);
string str23 = date2.Substring(o2 + 1);
if (Convert.ToInt32(str11) > Convert.ToInt32(str21))
{
}
else if (Convert.ToInt32(str12) > Convert.ToInt32(str22))
{
}
else if (Convert.ToInt32(str12) == Convert.ToInt32(str22) && Convert.ToInt32(str13) > Convert.ToInt32(str23))
{
}