CODEWITHSUNDEEP
c#datetime
Audrius Gr
Audrius Gr

Reputation: 45

C# subtract time (hours minutes)

Hello Everyone I have some interesting situation.

I want to count how many hours (in minutes) is from 20:00 to 01:00 AM, but i Don't know how, because what i have done is:

pabaigosLaikoLaukelis = 01:00;
pradziosLaikoLaukelis = 20:00;
TimeSpan dt = Convert.ToDateTime(pabaigosLaikoLaukelis)- Convert.ToDateTime(pradziosLaikoLaukelis);
int minutes = (int)dt.TotalMinutes;

And i get result -> -1140 minutes, but I need that answer to be just 5 hours from 20:00 to 01:00.

I know that it is quite easy, but i have no idea how to do it.

Upvotes: 4

Views: 37496

Answers (7)

Andrii Kalytiiuk
Andrii Kalytiiuk

Reputation: 1497

Use full date time strings that contain day part, to show that 01:00 AM is one day later than 20:00 - like following:

int minutes = Convert.ToDateTime("01/02/2012 01:00").Substract(Convert.ToDateTime("01/01/2012 20:00")).TotalMinutes;

Upvotes: 3

Ozan Kaya
Ozan Kaya

Reputation: 49

How about this:

pabaigosLaikoLaukelis = 01:00;
pradziosLaikoLaukelis = 20:00;
TimeSpan startTime = Convert.ToDateTime(pradziosLaikoLaukelis).TimeOfDay;
TimeSpan endTime = Convert.ToDateTime(pabaigosLaikoLaukelis).TimeOfDay;
TimeSpan diff = endTime > startTime ? endTime - startTime : endTime - startTime + TimeSpan.FromDays(1);
int minutes = (int)diff.TotalMinutes;

Upvotes: 0

Dustin Kingen
Dustin Kingen

Reputation: 21245

You need to add a day to the first TimeSpan and use TotalHours.

var pabaigosLaikoLaukelis = "01:00";
var pradziosLaikoLaukelis = "20:00";
var oneDayTimeSpan = new TimeSpan(1, 0, 0, 0);
TimeSpan dt = TimeSpan.Parse(pabaigosLaikoLaukelis).Add(oneDayTimeSpan) - TimeSpan.Parse(pradziosLaikoLaukelis);
int minutes = (int)dt.TotalHours; // 5 hours

Using associative operations:

var pabaigosLaikoLaukelis = "21:00";
var pradziosLaikoLaukelis = "20:00";
var leftHours = (int)TimeSpan.Parse(pabaigosLaikoLaukelis).TotalHours;
var rightHours = (int)TimeSpan.Parse(pradziosLaikoLaukelis).TotalHours;
// Now we do a Modulus operation which will assure
// 23 > hours > 0
// Make sure to check that leftHours != 0 or rightHours != 0
int hours = (Math.Abs(leftHours * rightHours) + leftHours) % rightHours; //Modulus
var hoursTimeSpan = TimeSpan.FromHours(hours);

Upvotes: 0

Thomas Andreè Wang
Thomas Andreè Wang

Reputation: 3429

you could do something like this

        //Datetime(Year,month,day,hour,min,sec)
        DateTime date1 = new DateTime(2012, 1, 1, 20, 0, 0);
        DateTime date2 = new DateTime(2012, 1, 2, 1, 0, 0);
        string minutes = (date2.Subtract(date1).TotalMinutes).ToString();

Tested and works 300 minutes (5 hours)

Upvotes: 10

Steve
Steve

Reputation: 216293

A bit of preparation of the two string variables is required before attempting data calculations

string pabaigosLaikoLaukelis = "01:00";
string pradziosLaikoLaukelis = "20:00";
pabaigosLaikoLaukelis = DateTime.Today.ToString("dd/MM/yyyy") + " " + pabaigosLaikoLaukelis;
pradziosLaikoLaukelis = DateTime.Today.AddDays(-1).ToString("dd/MM/yyyy") + " " + pradziosLaikoLaukelis;

TimeSpan dt = Convert.ToDateTime(pabaigosLaikoLaukelis) - Convert.ToDateTime(pradziosLaikoLaukelis);
Console.WriteLine("{0:D2}:{1:D2}", dt.Hours, dt.Minutes);

Upvotes: 0

Julián Urbano
Julián Urbano

Reputation: 8488

Be careful with adding one day to the endTime, because then the difference between 20:00 and 22:00 will be 26 hours instead of 2!

Just check whether the difference is positive (same day) or negative (next day)

string pabaigosLaikoLaukelis = "01:00";
string pradziosLaikoLaukelis = "20:00";
// This should be 5 hours
TimeSpan dt = Convert.ToDateTime(pabaigosLaikoLaukelis) - Convert.ToDateTime(pradziosLaikoLaukelis);
int hours = (int)dt.TotalHours;
hours = hours < 0 ? 24 + hours : hours;
// This should be 19 hours
dt = Convert.ToDateTime(pradziosLaikoLaukelis) - Convert.ToDateTime(pabaigosLaikoLaukelis);
hours = (int)dt.TotalHours;
hours = hours < 0 ? 24 + hours : hours;

Upvotes: 0

Rob
Rob

Reputation: 5588

You need to specify the Day, you are subracting (Today 1:00 AM) - (Today 8:00 PM)

I think you need to subract (Tommorrow 1:00 AM) - (Today 8:00 PM)

Upvotes: 0

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