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Add time duration to date using addHours() in c#

I want to add time duration to my datetime variable. I am reading the duration from a csv file. The format of duration is 0:29:40 or 1:29:40. When i add this to datetime variable it gives exception of incorrect format. How can I add the duration using this format. Previously I had duration as a simple integer like "6" or "7" but now the format is this "0:29:40" I don't know how to change my code to accommodate this format.
Previously i was doing this
double hours = Convert.ToDouble(row.Cells[2].Value.ToString());
DateTime newdate = finaldate.AddHours(hours);
row.Cells[2].Value.ToString() reads the value from csv
Any help is appreciated, Thanks

You don't need to parse to a double. Parse to a TimeSpan. Something like:
var source = "0:29:40";
var ts = TimeSpan.Parse(source);
Now ts is your time span. And the nice thing with TimeSpan is you can just add it to a DateTime:
DateTime newdate = finaldate + ts;

You are going to need to use the TimeSpan.Parse() or TimeSpan.ParseExact() method to properly parse your string and then simply add that TimeSpan result to your existing date:
var time = TimeSpan.Parse(row.Cells[2].Value.ToString());
DateTime newDate = finalDate.Add(time);
If you need to explicitly specify what each of the values of your time represent, then the TimeSpan.ParseExact() method will allow you to provide a formatting string to specify this:
// This will assume that 1:29:40 is hours, minutes, and seconds
var time = TimeSpan.ParseExact(row.Cells[2].Value.ToString(), #"h\:m\:s", null);

Displaying a formatted TimeSpan as string

I'd like to display a TimeSpan value, formatted as mm:ss (minutes, seconds).
The code currently performs this like this:
var timeSpan = GetTimeUntilNextEvent();
var str = DateTime.MinValue.Add(timeSpan).ToString(#"mm\:ss");
I wonder whether that is correct code. I saw other samples that show this technique, but I am not really sure what is the reason for adding something to the MinValue of DateTime.
Why cannot this code be used ? It seems to product a valid result.
var str = DateTime.FromBinary(0).Add(timeSpan).ToString(#"mm\:ss");

You don't need DateTime to format a TimeSpan.
You could simply use the timespan ToString() method:
TimeSpan timeSpan = new TimeSpan(5, 12, 2);
String str = timeSpan.ToString(#"mm\:ss"));
Also see Link.

How to Convert string "07:35" (HH:MM) to TimeSpan

I would like to know if there is a way to convert a 24 Hour time formatted string to a TimeSpan.
Right now I have a "old fashion style":
string stringTime = "07:35";
string[] values = stringTime.Split(':');
TimeSpan ts = new TimeSpan(values[0], values[1], 0);

While correct that this will work:
TimeSpan time = TimeSpan.Parse("07:35");
And if you are using it for validation...
TimeSpan time;
if (!TimeSpan.TryParse("07:35", out time))
{
// handle validation error
}
Consider that TimeSpan is primarily intended to work with elapsed time, rather than time-of-day. It will accept values larger than 24 hours, and will accept negative values also.
If you need to validate that the input string is a valid time-of-day (>= 00:00 and < 24:00), then you should consider this instead:
DateTime dt;
if (!DateTime.TryParseExact("07:35", "HH:mm", CultureInfo.InvariantCulture,
DateTimeStyles.None, out dt))
{
// handle validation error
}
TimeSpan time = dt.TimeOfDay;
As an added benefit, this will also parse 12-hour formatted times when an AM or PM is included, as long as you provide the appropriate format string, such as "h:mm tt".

Try
var ts = TimeSpan.Parse(stringTime);
With a newer .NET you also have
TimeSpan ts;
if(!TimeSpan.TryParse(stringTime, out ts)){
// throw exception or whatnot
}
// ts now has a valid format
This is the general idiom for parsing strings in .NET with the first version handling erroneous string by throwing FormatException and the latter letting the Boolean TryParse give you the information directly.

Use TimeSpan.Parse to convert the string
http://msdn.microsoft.com/en-us/library/system.timespan.parse(v=vs.110).aspx

You can convert the time using the following code.
TimeSpan _time = TimeSpan.Parse("07:35");
But if you want to get the current time of the day you can use the following code:
TimeSpan _CurrentTime = DateTime.Now.TimeOfDay;
The result will be:
03:54:35.7763461
With a object cantain the Hours, Minutes, Seconds, Ticks and etc.

Convert TimeSpan from format "hh:mm:ss" to "hh:mm"

I want to show in a TextBox only hour and minutes
var test = dataRow.Field<TimeSpan>("fstart").ToString();
//test ="08:00:00"
var tb = (TextBox) gridViewRow.Cells[2].FindControl("fstart");
tb.Text = test;
how to show only hours and minutes "hh.mm"

You need to convert your data to TimeSpan and then use format:"hh\:mm"
string test ="08:00:00";
TimeSpan ts = TimeSpan.Parse(test);
Console.Write(ts.ToString(#"hh\:mm"));
In your case:
var test = dataRow.Field<TimeSpan>("fstart").ToString(#"hh\:mm"));
Remember to escape the colon :
You may see: Custom TimeSpan Format Strings

There is no need to convert from hh.mm.ss to hh.mm. TimeSpan is stored as a number of ticks (1 tick == 100 nanoseconds) and has no inherent format. What you have to do, is to convert the TimeSpan into a human readable string! This involves formatting. If you do not specify a format explicitly, a default format will be used. In this case hh.mm.ss.
string formatted = timespan.ToString(#"hh\.mm");
Note: This overload of ToString exists since .NET 4.0. It does not support date and time placeholder separator symbols! Therefore you must include them as (escaped) string literals.
The usual way of formatting strings seems not to work for some odd reason (tested with .NET 3.5). (It does not make any difference whether you escape the separator symbol or not):
var timespan = TimeSpan.FromSeconds(1234);
string formatted = String.Format(#"{0:hh\.mm}", timespan); // ==> 00:20:34
However, you can construct the string like this
string formatted =
String.Format("{0:00}.{1:00}", Math.Floor(timespan.TotalHours), timespan.Minutes);
or starting with VS2015 / C# 6.0, using string interpolation:
string formatted = $#"{timespan:hh\:mm}";

You can use TimeSpan methods:
ToString("hh':'mm")
// or
ToString(#"hh\:mm")
Also check all available formats here http://msdn.microsoft.com/en-us/library/8kb3ddd4.aspx

var test = dataRow.Field<TimeSpan>("fstart").ToString("hh.mm");
//test ="08:00"
var tb = (TextBox) gridViewRow.Cells[2].FindControl("fstart");
tb.Text = test;

I know this is a very old question. If anyone wants to show single-digit hours when your hours are a single digit then you can use
var hoursWithMinutes = TimeSpan.FromHours(hours).ToString(#"h\:mm")
This way, when your hours are double-digit I mean greater than 9 then it will be showing 10:00 something like that.

The previous solutions don't run if hours>24, try this solution if you have time in minutes very big
int minutes = 159000;
TimeSpan t = new TimeSpan(0, minutes, 0);
String HOURS = Math.Round(t.TotalHours, 0).ToString();
if (HOURS.Length==1)
{
HOURS = "0"+HOURS;
}
String MINUTES = t.Minutes.ToString();
if (MINUTES.Length == 1)
{
MINUTES = "0" + MINUTES;
}
String RESULT = HOURS + ":" + MINUTES;

You can achieve this by:
var hhmm = TimeSpan.FromMinutes(minutes).ToString(#"hh\:mm")

How to set current time to a value

I was just wondering if there is a way to get the current time and set it into a value.
If its 12:06 AM.. I want to get that time and set it into currentTime.
Example
float currentTime = 0;
currentTime = 12.06;

As others have mentioned, the DateTime class would be ideal for this, and to work out the difference between 2 date/times:
DateTime end = DateTime.Now;
DateTime start = new DateTime(2011, 12, 5, 12, 6,0);
double hours = (end - start).TotalHours;
The subtraction of DateTime objects results in a TimeSpan object that you can use to see the hours/minutes etc.

try DateTime class
DateTime dt = DateTime.Now;

Is this what you're looking for?
DateTime currentTime;
currentTime = DateTime.Now;

Don't use floats or strings. You can do all kinds of cool things using DateTime.
Here's how you'd get the hours that someone worked:
var clockIn = new DateTime(2011,12,4,9,0,0); // December 4th, 9 AM
var clockOut = new DateTime(2011,12,4,17,0,0); // December 4th, 5 PM
var duration = clockOut - clockIn; // TimeSpan
Console.Write(duration.TotalHours); // 8

A few people have mentioned how, but as a 'better' recommendation you should use
DateTime currentTime = DateTime.UtcNow
Otherwise you have issues when the clocks go back, if your timing code is run on those days. (plus it is far easier to alter the UTC time to local time than it is to convert a '1am' to UTC (as there will be two of them when the clocks go back)

Well if you really what it as a float then try:
var currentDate = DateTime.Now;
float currentTime = float.Parse((currentDate.Hour > 12 ? currentDate.Hour -12 :
currentDate.Hour) + "." + currentDate.Minute);
I wouldn't recommend comparing dates or time with floats. A better options would be to use timespans.

You should be using a Timespan instance for time related values, you can use the flexibility to get the required values like
TimeSpan ts = DateTime.Now.TimeOfDay;
ts.ToString("hh:mm") // this could be what you are looking for
You could then use ts.TotalHours which would give you fractional hours (as a double) else you could construct a string specifically using ts.Hours ..ts.Minutes play around and it could be prove useful.

Try the following:
DateTime StartTime=StartTime value;
DateTime CurrentTime=DateTime.Now;
TimeSpan dt = CurrentTime.Subtract(StartTime);
In dt you will get a working time period.

If you want to have the difference between two times, then do this:
DateTime dateOne = DateTime.Parse(enteredTime);
DateTime dateTwo = DateTime.Now;
TimeSpan difference = dateOne - dateTwo;