I'm working on a C# application, where I'm doing some things and I want to display both the start, intermediate and end timestamps, and now I would like to add their time differences.
I figured it would be easy:
Console.WriteLine($"Start time: {DT_Start.ToString("yyyy-MM-dd HH:mm:ss.fff")}");
Console.WriteLine($"Intermediate time: {DT_Intermediate.ToString("yyyy-MM-dd HH:mm:ss.fff")}");
Console.WriteLine($"End time: {DT_End.ToString("yyyy-MM-dd HH:mm:ss.fff")}");
This is working great. So I thought it would be equally easy to show the differences, so I started with:
Console.WriteLine($"Elapsed times: [{(DT_Intermediate - DT_Start).ToString("HH:mm:ss.fff")}] " +
$"and [{(DT_End - DT_Intermediate).ToString("HH:mm:ss.fff")}]");
I had dropped the year, month and day because everything is done in the same day. This did not work, so I decided to add those entries, but it still does not work:
Console.WriteLine($"Elapsed times: [{(DT_Intermediate - DT_Start).ToString("yyyy-MM-dd HH:mm:ss.fff")}] " +
$"and [{(DT_End - DT_Intermediate).ToString("yyyy-MM-dd HH:mm:ss.fff")}]");
So, in C#, you can show datetime objects and you can subtract them. The results, when debugging, are very similar but if you try to show that information in the same way, you get the error message System.FormatException: 'Input string was not in the correct format.'.
Is there a format I can use for both DateTime and TimeSpan objects? (I've seen that the difference between two DateTime objects would be a TimeSpan object)
As you have discovered yourself, the difference between two DateTime objects is a TimeSpan which just represents the difference of time that has passed. Since a TimeSpan is not linked to a calendar date, you cannot format it using calendar specific things like months and years.
However, your initial approach of only showing hours, minutes and seconds does work just fine. However, you will need to escape the colon and dot when wanting to use it in a TimeSpan format string. And also, the HH for the hours in the DateTime is written as lower-case hh for TimeSpan:
Console.WriteLine((DT_Intermediate - DT_Start).ToString("hh\\:mm\\:ss\\.fff"));
// ^^^^ ^^ ^^
// lower-case hh and escaped characters
So in your example, this should work:
Console.WriteLine($"Elapsed times: [{(DT_Intermediate - DT_Start).ToString("hh\\:mm\\:ss\\.fff")}] " +
$"and [{(DT_End - DT_Intermediate).ToString("hh\\:mm\\:ss\\.fff")}]");
Note that the TimeSpan also supports days as part of the difference, so if the number of hours in your difference surpasses 24, you will be missing this difference until you also include the number of days using the format specifier d in your result.
You can read more about formatting TimeSpan in the documentation about custom format strings.
You can use the DateTime.Subtract Method, it accepts DateTime and TimeSpan Object input.
https://learn.microsoft.com/de-de/dotnet/api/system.datetime.subtract?view=net-7.0
Related
I want to be able to parse strings of time (hours, minutes, seconds) where the hours run from 0 to 23, and where the preceding zero for one-digit hours is optional.
Examples of time strings that I want to be able to parse into valid DateTime objects:
212540
061525
94505
I am trying to use the C# method DateTime.ParseExact to manage the parsing, but I cannot for the life of it come up with a format string that can handle the "single-digit hour without preceding zero" scenario.
How should I specify the DateTime.ParseExact format string to sufficiently parse all examples above with the same line of code?
Inspired by the MSDN page on custom date and time formats, I have tried the following approaches:
DateTime.ParseExact(time_string, "Hmmss", CultureInfo.InvariantCulture);
DateTime.ParseExact(time_string, "%Hmmss", CultureInfo.InvariantCulture);
DateTime.ParseExact(time_string, "HHmmss", CultureInfo.InvariantCulture);
All these format strings work for the first two example cases above, but faced with a single-digit hour and no preceding zero, all formulations throw a FormatException.
You can insert delimiters between hours, minutes and seconds like this:
string timeString = "94505";
string formatedTimeString = Regex.Replace(str, #"\d{1,2}(?=(\d{2})+$)", "$&:");
var datetime = DateTime.ParseExact(formatedTimeString, "H:mm:ss", CultureInfo.InvariantCulture);
UPDATE:
I've found the cause of failure when parsing "94505" with format string "Hmmss":
What's happening is that H, m and s actually grabs two digits when they can, even if there won't be enough digits for the rest of the format. So the for example with the format Hmm and the digits 123, H would grab 12 and there would only be a 3 left. And mm requires two digits, so it fails.
So basically you have two options for handling the "single-digit hour without preceding zero" scenario:
Change time format: place hours to the end (for example, "ssmmH" or "mmssH") or use delimiters (for example, "H:mm:ss")
Modify the string like I've suggested earlier or like keyboardP has.
You could pad your input string if you know that you'll always have six characters.
string input = "94505";
if(input.Length < 6)
input = input.PadLeft(6, '0');
(Or use input.Length == 5 if you have other valid formats that are shorter).
What about using:
DateTime.ParseExact(time_string, "Hmmss", CultureInfo.InvariantCulture).ToString("HH:mm:ss")
I had some code that crunched a lot of data, so I started it on Thursday and left it running over the weekend. On Monday, I have come back and seen that it finished. I used a stopwatch function to track the length of time the code ran for. However, I ended up with
Elapsed: 2.18:57:55.xxx
I understand that it's output is normally H:M:SS, but don't understand the first digit, especially since it's been running for days. Did it just convert from hours to days? Did I leave it running so long that it broke?
EDIT: Sorry, I didn't mean that it finished on Monday. I just meant that BY Monday (when I returned to the computer), it was done.
Yes - that's the format of TimeSpan.ToString:
The returned string is formatted with the "c" format specifier and has the following format:
[-][d.]hh:mm:ss[.fffffff]
Elements in square brackets ([ and ]) may not be included in the returned string. Colons and periods (: and.) are literal characters. The non-literal elements are listed in the following table. Note that the string returned by the ToString() method is not culture-sensitive.
Since there's not a format specifier that shows total hours, you'll need to calculate it. If you want the hours to be shown as a single number then use:
TimeSpan ts = new TimeSpan(2,18,57,55);
var output = string.Format("{0}:{1}",
ts.Days*24 + ts.Hours,
ts.ToString("mm\\:ss\\.ffff"));
//output = `66:57:55.0000`
That's expected behaviour. From the docs for Timespan.ToString():
The returned string is formatted with the "c" format specifier and has the following format:
[-][d.]hh:mm:ss[.fffffff]
"d" - The number of days in the time interval. This element is omitted if the time interval is less than one day.
Our webservice uses the Datetime.parse method to convert data from an xml to DateTime format. It parses Date and time strings separately and adds it together like this -
DateTime.Parse(Date_string).add(TimeSpan.Parse(Time_string)).
Code was working fine except for a few hours last week. Time was showing as 12 hours ahead of actual time. For example, 01/01/2011 10:00:00 will be parsed as 01/01/2011 22:00:00. Most of the requests during that time were processed with datetime values 12 hours ahead of actual time though some were processed correctly. It is working fine now and haven't seen it after that.
Has anyone seen a issue like this?
You say "Code was working fine except for a few hours last week", but you didn't specify exactly when that was or what time zone you are in. Any chance it was around a daylight savings time change?
You shouldn't use TimeSpan.Parse at all. A TimeSpan does NOT represent the time-of-day, despite its appearance as hh:mm:ss. A TimeSpan represents a fixed DURATION of time.
If you really are given separate date and time strings, join them together before parsing, such as:
DateTime dt = DateTime.Parse(date_string + " " + time_string);
You should also be aware of the timezone implications of the string you are sending in. See the MSDN article on DateTime.Parse for further details.
I am trying to format a TimeSpan element in the format of "[minutes]:[seconds]". In this format, 2 minutes and 8 seconds would look like "02:08". I have tried a variety of options with String.Format and the ToString methods, but I get a FormatException. This is what I'm currently trying:
DateTime startTime = DateTime.Now;
// Do Stuff
TimeSpan duration = DateTime.Now.Subtract(startTime);
Console.WriteLine("[paragraph of information] Total Duration: " + duration.ToString("mm:ss"));
What am I doing wrong? How do I format a TimeSpan element using my desired format?
NOTE: This answer applies to .NET 4.0 only.
The colon character is a literal and needs to be wrapped in single quotes:
duration.ToString("mm':'ss")
From the MSDN documentation:
The custom TimeSpan format specifiers
do not include placeholder separator
symbols, such as the symbols that
separate days from hours, hours from
minutes, or seconds from fractional
seconds. Instead, these symbols must
be included in the custom format
string as string literals.
Try this:
Console.WriteLine("{0:D2}:{1:D2}", duration.Minutes, duration.Seconds);
Custom formatting of System.TimeSpan was added in .Net 4, so you can now do the following:
string.Format("{0:mm\\:ss}", myTimeSpan);
(UPDATE) and here is an example using C# 6 string interpolation:
$"{myTimeSpan:hh\\:mm\\:ss}"; //example output 15:36:15
In short you now need to escape the ":" character with a "\" (which itself must be escaped unless you're using a verbatim string).
This excerpt from the MSDN Custom TimeSpan Format Strings page explains about escaping the ":" and "." charecters in a format string:
The custom TimeSpan format specifiers do not include placeholder separator symbols, such as the symbols that separate days from hours, hours from minutes, or seconds from fractional seconds. Instead, these symbols must be included in the custom format string as string literals. For example, "dd.hh:mm" defines a period (.) as the separator between days and hours, and a colon (:) as the separator between hours and minutes.
For some mysterious reason TimeSpan never got the ToString() overloads that support formatting until .NET 4.0. For earlier releases, as long as it is positive, you can hijack DateTime.ToString():
TimeSpan ts = new TimeSpan(0, 2, 8);
string s = new DateTime(ts.Ticks).ToString("mm:ss");
The date and time format strings only apply to DateTime and DateTimeOffset. Yo can use a normal format string, though:
string.Format("{0}:{1:00}", Math.Truncate(duration.TotalMinutes), duration.Seconds)
Note that using TotalMinutes here ensures that the result is still correct when it took longer than 60 minutes.
Try this:
DateTime startTime = DateTime.Now;
// Do Stuff
TimeSpan duration = DateTime.Now.Subtract(startTime);
Console.WriteLine("[paragraph of information] Total Duration: " + duration.Minutes.ToString("00") + ":" + duration.Seconds.ToString("00"));
Based on this MSDN page describing the ToString method of TimeSpan, I'm somewhat surprised that you can even compile the code above. TimeSpan doesn't have a ToString() overload that accepts only one string.
The article also shows a function you can coyp and use for formatting a TimeSpan.
you could always do:
string.Format("{0}:{1}", duration.Minutes, duration.Seconds);
You can use the below code.
TimeSpan tSpan = TimeSpan.FromSeconds(allTotalInMinutes);
string tTime = string.Format("{1:D2}:{2:D2}", tSpan.Minutes, tSpan.Seconds);
It will show ie 34:45 format.
Hope it will help you.
TimeSpan t = TimeSpan.Parse("13:45:43");
Console.WriteLine(#"Timespan is {0}", String.Format(#"{0:yy\:MM\:dd\:hh\:mm\:ss}", t));
I am working on an algorithm in C# to calculate a past DateTime based on an input string with the following characteristics:
The string contains an integer followed by either 'D', 'M' or 'Y', such as "1D" or "90M".
The output will be DateTime.Now minus the corresponding number of days, months or years.
The issue I am having is that if, for instance, I switch the input string on a Regex (D, M or Y) and subtract the corresponding TimeSpan from DateTime.Now, the new TimeSpan() constructor does not accept months or years, only days.
if (new Regex(#"[0-9]+D").IsMatch(value))
{
newDate = DateTime.Now - TimeSpan(Int32.Parse(value.Replace("D", "")), 0, 0);
}
This logic is fine if the input string is in days, but the constructor for TimeSpan does not accept months or years, and it would be incredibly inaccurate if I assumed each month had 30 days, or each year had 365 days.
Does anyone have thoughts on how to implement this algorithm?
Thanks!
DateTime has AddMonths, AddDays and AddYears methods. Use them with minus to substract
Could you not rather try using the AddDays/AddMonths/AddYears but with negative numbers?
From DateTime.AddDays Method
The value parameter can be negative or
positive.
And then maybe just implement a switch stament to apply the appropriate Add method.
To subtract months, I create a new DateTime and just evaluate month/year. So 1/2010 - 6 months would be 6/2010... once you have the month/year established, you can look at the original datetime day component, and ensure it fits within the month.
That's what I did. Year was evaluated the same way. Subtracting days is easy; use the TimeSpan component to do it.
Remember that you can add negative amounts as well and check out this method and this one.
http://msdn.microsoft.com/en-us/library/3z48198e.aspx
TimeSpan.TryParse accepts very close to your string as long as you can fits its formatting OR convert from yours to its.