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How to subtract two times from two datetime and calculate is elapse time from 61 seconds or not?

I'm working on an asp.net core MVC project. This project about identifying online and offline users, I have two datetime, one of the stores in a database, and another is current datetime, and I must know that time stored in a database elapsed from 61 seconds or not?
I subtract two Datetime and finally use TotalSeconds property.but my output is -22095 or 2319208 and so on.
public void CheckUserStatus()
{
DateTime now = DateTime.Now;
var userTime = _context.Sessions.Where(x => x.LastOnline).Select(x => new {x.LastConnectTime, x.Id});
foreach (var time in userTime)
{
TimeSpan diffrence = now.Subtract(time.LastConnectTime);
int mytime = Convert.ToInt32(diffrence.TotalSeconds);
if ( mytime < 61)
{
Console.WriteLine(time.Id);
}
}
}
I expect out of time base on seconds, for example, right now my output is -22095 or 2319208, and so on but I don't know 2319208 is a regular time or not?

You can easily check that like this :
DateTime now = DateTime.Now;
TimeSpan past = now - now.Subtract(TimeSpan.FromSeconds(60));
TimeSpan post = now - now.Subtract(TimeSpan.FromSeconds(61));
Console.WriteLine(now);
// Should be False: Passed time is less than 60 seconds
Console.WriteLine(past.TotalSeconds > 60);
// Should be True: Passed time is more than 60 seconds
Console.WriteLine(post.TotalSeconds > 60);

Better way to get Interval bounds when only time is given

I have to find out the limits of interval i.e upper-bound and lower-bound of an interval based on interval type when datetime is given.
Example: say given time = 12:05 (then, this lies in the interval range 12:00 - 1:00 if interval type is hourly; 12:00 - 12:30 if interval type is half-an hour based;
12:00 - 12:15 if interval type is quarterly. likewise interval type can be anything.
Currently i am loading all different set of interval ranges in a dictionary object on an application load and then i fetch interval range from this dictionary for the given time.
Sorry, I know this problem statement looks simple but couldn't think of other approaches as of now. It would be helpful if someone can help me here. Thanks in advance.

You can calculate the range start by dividing the total minutes by your interval and then subtracting the remainder from the total minutes. After that, you can easily get the end of the range.
First, you need to get the time part from your DateTime object as TimeSpan by using DateTime.TimeOfDay. Then use TimeSpan.TotalMinutes.
Here's a good start:
public class TimeRange
{
public TimeRange(TimeSpan from, TimeSpan to)
{
From = from;
To = to;
}
public TimeSpan From { get; set; }
public TimeSpan To { get; set; }
}
public TimeRange GetRange(DateTime d, int minutesInterval)
{
TimeSpan time = d.TimeOfDay;
var from = time.TotalMinutes - (time.TotalMinutes % minutesInterval);
var to = from + minutesInterval;
return new TimeRange(TimeSpan.FromMinutes(from), TimeSpan.FromMinutes(to));
}
For clarity, I created a simple class called TimeRange to represent the start and end of the interval range. You can, however, feel free to handle this in a different way.
Usage:
DateTime d = DateTime.Now;
TimeRange range = GetRange(d, 60);
//TimeRange range = GetRange(d, 15);
Console.WriteLine("From: {0}\r\nTo: {1}", range.From, range.To);
Try it online.

Adding 1 second to TimeSpan not working

I have this code:
private void TimePlayedTimer_Start()
{
timePlayedStr = "00:00:00";
timePlayed = new DispatcherTimer();
timePlayed.Tick += timePlayedTimer_Tick;
timePlayed.Interval = new TimeSpan(0, 0, 0, 1);
timePlayed.Start();
}
void timePlayedTimer_Tick(object sender, object e)
{
TimeSpan ts = TimeSpan.Parse(timePlayedStr);
ts = ts.Add(TimeSpan.FromSeconds(1));
timePlayedStr = ts.ToString();
}
When I debug this line by line, TimeSpan ts would equal "00:00:00" but after line ts = ts.Add(TimeSpan.FromSeconds(1)); it would some how have properties TotalDays = 2.313232439423 , TotalHours = 0.000555555 , TotalMilliseconds = 2000 rather than adding a 1 to the TotalSeconds properties I get these property values returned.
Does anyone know what I am doing wrong?
PS: I am just trying to add a second to the TimeSpan after every tick

The value for TotalDays is actually 2.31481481481481E-05, i.e. 0.0000231481481481481.
The value that you get is exactly what's expected at the second tick, you didn't manage to debug the first tick, and you are just interpreting the values wrong.
The TotalDays, TotalHours and TotalMilliseconds properties show the total value in the TimeSpan translated to that specific measurement, they don't form a value together.
2 seconds is the same as 2000 milliseconds, and the same as 0.000555555 hours.
If you want to look at the components in the value, you should look at the Days, Hours, Minutes, Seconds and Milliseconds properties. There you will find that the Seconds property is 2 and all the others are zero.

I think you're misreading the TotalDays value. When I run similar code I get my TotalDays value of 1.15740740740741E-05. That likely makes sense, one second is probably roughly that fraction of a day.
The Total* properties represent the overall value of the TimeSpan, not the discrete value of each portion of the TimeSpan.
Days, Hours, and Minutes will all be 0, but the Total* properties will represent the entirety of the value, even if those parts are fractional.

How to divide time in equal slots in C#

I want to divide time in equal intervals in C#. Like from 3:00pm to 6:00pm create time intervals with a gap of 45 minutes (e.g, 3:00pm, 3:45pm, 4:30pm .... 6:00pm.
How can I acheive this in C# ?

You can use the DateTime.Ticks property to define your intervals, and then create a series of DateTime objects based on your defined interval. The example below can be run in LINQpad. Per the documentation, there are 10000000 ticks in one second. With that in mind:
var startTS = Convert.ToDateTime("6/17/2018 15:00:00");
var endTS = Convert.ToDateTime("6/17/2018 18:00:00");
long ticksPerSecond = 10000000;
long ticksPerMinute = ticksPerSecond * 60;
long ticksPer45Min = ticksPerMinute * 45;
long startTSInTicks = startTS.Ticks;
long endTsInTicks = endTS.Ticks;
for(long i = startTSInTicks; i <= endTsInTicks; i+=ticksPer45Min)
{
new DateTime(i).Dump();
}
In LINQpad, the output looks like this:
6/17/2018 15:00:00
6/17/2018 15:45:00
6/17/2018 16:30:00
6/17/2018 17:15:00

Try this
DateTime StartTime = DateTime.Parse("3:0:0");//If pm it should be 15
DateTime EndTime = DateTime.Parse("6:0:0");//If pm it should be 18
while (StartTime!=EndTime)
{
double minuts = +45;
StartTime = StartTime.AddMinutes(minuts);
}
Hope this helps

Datetime.AddMinutes(double value) should do what you are looking for. Just keep on adding until the result of the addition goes over the maximum date/time you have.
NOTE: This assumes you know your interval. If, on the other hand, you require to split a time span in a equal n parts you would require a different approach, as shown here.

Not allowing a user to put "Clock Out" time < "Clock In" time?

Public void Fee()
{
TimeSpan span1 = TimeSpan.FromHours(dtmIn.Value.Hour);
TimeSpan span2 = TimeSpan.FromHours(dtmOut.Value.Hour);
TimeSpan span3 = TimeSpan.FromMinutes(dtmIn.Value.Minute);
TimeSpan span4 = TimeSpan.FromMinutes(dtmOut.Value.Minute);
TimeSpan span5 = span2.Subtract(span1) + span4.Subtract(span3);
lblTotal.Text = (span5.TotalHours * 3).ToString("$#.00");
}
I do not want the user to be able to be able to clock in during PM and clock out during AM(basically overnight working). Also, not allowing the clock out time being before the clock in time.

You should call new TimeSpan(hours, minutes, seconds: 0) and check whether the in TimeSpan is > the out TimeSpan.

It appears from your code sample that dtmIn and dtmOut are nullable DateTime variables. If so, all you have to do is this:
if (dtmIn.Value >= dtmOut.Value)
{
//'in' time is equal to or greater than 'out' time
... show my error message ...
}
Of course you will need to ensure the DateTime? variables have a value (i.e. do appropriate error checking before using them in the expression).

You probably need to be a little more specific with your logic. Do you mean...
The user should be able to work overnight? If so, that means you need to check to make sure that the date they clocked in is the same as the date they clocked out. `
For example...
if (dtmIn.Value.Date != dtmOut.Value.Date)
{
...
}
The user should not be able to work more than 24 hours? If so, you should subtract the two dates and use the resulting TimeSpan to see how many days they worked.
For example...
if ((dtmOut.Value - dtmIn.Value).TotalDays > 1)
{
...
}
In neither case should you check the time explicitly. For one, if I worked 25 hours then my check out time would still be after the check in time.