Develop Reference

c# Birthday month day limit

I'm not a C# expert so please keep that in mind while I ask this:
In my C# I have a forms project where the user enters the year,month and day they were born and it tells them the day of week their birthday was on.
I want to make sure the user doesn't enter a date that doesn't exist example:
Feb 30 2018.
So, I want to create a popup message that says "date doesn't exist" to do this I created this code:
static string FindDay(int year, int month, int day)
{
//The reason why we are using a new keyword is because i belive: we are creating a new object and to do that you must use a new keyword.
//DateTime is its own data type like int or string.
DateTime birthdayDate = new DateTime(year, month, day);
string dayOfWeek = birthdayDate.DayOfWeek.ToString(); //Don't confuse the local dayOfWeek varible with the DayOfWeek property
return dayOfWeek;
}
private void FindButton_Click(object sender, EventArgs e)
{
//The reason(I think) that we are casting to int data types is because its a "DateTime" data type.
int year = (int)numericYear.Value;
int month = (int)numericMonth.Value;
int day = (int)numericDay.Value;
//Date checking to maek sure date isn't invaild.
int maxDays = DateTime.DaysInMonth(year, month);
if (day > maxDays)
{
MessageBox.Show("Invaild date");
}
string dayString = FindDay(year, month, day);
MessageBox.Show("You were born on a:" + dayString);
}
But when I run in the program everything runs fine and the message pops up and then after the message I see this:
ERROR:
System.ArgumentOutOfRangeException: 'Year, Month, and Day parameters describe an un-representable DateTime.'
And it pops up at
string dayOfWeek = birthdayDate.DayOfWeek.ToString();
How can I fix this issue and why is it happening?

int maxDays = DateTime.DaysInMonth( year, month ); // set a breakpoint here, and see what happens
if ( day > maxDays )
{
MessageBox.Show("Invaild date");
}
else
{
string dayString = FindDay(year, month, day);
MessageBox.Show("You were born on a:" + dayString);
}

If you don't have to show message to explain why the date is not valid you can simply TryParseExact it into a DateTime.
No need to convert to int, To check the number of day in the month.
var inputs = new List<inputDate>
{
new inputDate(1,1,2018),
new inputDate(32,1,2018),
new inputDate(1,13,2018),
new inputDate(1,1,-2018)
};
foreach (var input in inputs)
{
GetDayOfBirth(input);
}
private void GetDayOfBirth(inputDate input)
{
CultureInfo invC = CultureInfo.InvariantCulture;
if (DateTime.TryParseExact(
$"{input.D}/{input.M}/{input.Y}",
$"d/M/yyyy",
invC,
DateTimeStyles.None,
out DateTime birthday)
)
{
Console.WriteLine("You were born on a:" + birthday.DayOfWeek);
return;
}
Console.WriteLine("Invalid date");
}

Code block repeating when I want to implement try and catch exception

I'm writing a C# console application where you enter your name and birthdate in yyyy/mm/dd format to have the console tell you your age in years and months. Now I've got that part figured out and it works. Until I tried to also implement a try and catch exception to check if the date you entered was in the right format. If not it should tell you to try again 3 times before telling you the date format is incorrect and then quitting the app.
Now the problem is the app works sort of, but it tells you the date format is incorrect even when it isn't. Then still continues to give the correct output after looping through the app that asks for name and date of birth 3 times. This is the code I have so far(I know the year month output is a bit messy I just spent way too long testing too much stuff to try and change it now, I am open to improvements and changes though):
namespace CSConsoleDateTimeTypes
{
class Program
{
static int Count = 0;
static void Main(string[] args)
{ EnterDate(); }
static void EnterDate()
{
string userName, enteredDoBString;
Console.WriteLine("Enter your name:");
userName = Console.ReadLine();
Console.WriteLine("Enter your date of birth in the format yyyy/mm/dd:");
enteredDoBString = Console.ReadLine();
string dateString = Console.ReadLine();
parseDateString(dateString);
DateTime enteredDoB = DateTime.Parse(enteredDoBString);
Console.WriteLine("Your DoB is: {0}", enteredDoB);
DateTime dateToday = DateTime.Today;
if (dateToday < enteredDoB)
{
DateTime date4 = dateToday;
dateToday = enteredDoB;
enteredDoB = date4;
}
TimeSpan ts = dateToday - enteredDoB;
//total days (irrelevant to the application though)
Console.WriteLine(ts.TotalDays);
//total years
int years = dateToday.Year - enteredDoB.Year;
int months = 0;
//Total months
if (dateToday.Month < enteredDoB.Month)
{
months = 12 - dateToday.Month + enteredDoB.Month;
}
else
{
months = enteredDoB.Month - dateToday.Month;
}
if (months > 12)
{
Console.WriteLine("Years: {0}, Months: {1}", years - 1, 12 - (months - 12));
}
else if (months < 0)
{
Console.WriteLine("Years: {0}, Months: {1}", years, months - months);
}
else
{
Console.WriteLine("Years: {0}, Months: {1}", years, months);
}
Console.ReadKey();
Console.ReadKey();
}
static void parseDateString(string datestring)
{
try
{
DateTime date3 = DateTime.Parse(datestring, System.Globalization.CultureInfo.InvariantCulture);
date3.ToShortDateString();
Console.ReadKey();
}
catch (Exception e)
{
Console.WriteLine(e.Message);
//if date was entered incorrectly 3 times, the application should exit..
Count++;
if (Count < 3)
{
EnterDate();
}
else
{
Console.WriteLine("\aSorry date still not in correct format - Press any key to exit the application");
Console.ReadKey();
}
}
}
}
}
This is the output it gives when I launch the app and it finishes running through all the code after my inputs:
Enter your name:
gerrit
Enter your date of birth in the format yyyy/mm/dd:
1997/02/13
String was not recognized as a valid DateTime.
Enter your name:
gerrit
Enter your date of birth in the format yyyy/mm/dd:
1997/02/13
String was not recognized as a valid DateTime.
Enter your name:
gerrit
Enter your date of birth in the format yyyy/mm/dd:
1997/02/13
String was not recognized as a valid DateTime.
Sorry date still not in correct format - Press any key to exit the application
Your DoB is: 1997/02/13 12:00:00 AM
7294
Years: 20, Months: 0
Your DoB is: 1997/02/13 12:00:00 AM
7294
Years: 20, Months: 0
Your DoB is: 1997/02/13 12:00:00 AM
7294
Years: 20, Months: 0
As you can see it asks for name and date of birth 3 times and still telling me date format is incorrect then it gives the correct output (Your DoB is: 1997/02/13 12:00:00 AM
7294
Years: 20, Months: 0) 3 times
It should ask once and output once but I can't figure out how to do it. Any help would be highly appreciated.
Here is a screenshot of the console output if it helps at all
http://i.imgur.com/qUpF0g2.png

I changed a little your code.
I don't have checked the rest of your code, only to ask the date.
private static void Main(string[] args)
{
EnterDate();
}
private static void EnterDate()
{
Console.WriteLine("Enter your name:");
var userName = Console.ReadLine();
// ask for date
var enteredDoBString = AskForDate();
if (enteredDoBString == null)
return;
DateTime enteredDoB = DateTime.Parse(enteredDoBString);
Console.WriteLine($"Your DoB is: {enteredDoB}");
DateTime dateToday = DateTime.Today;
if (dateToday < enteredDoB)
{
DateTime date4 = dateToday;
dateToday = enteredDoB;
enteredDoB = date4;
}
TimeSpan ts = dateToday - enteredDoB;
// total days (irrelevant to the application though)
Console.WriteLine(ts.TotalDays);
// total years
var years = dateToday.Year - enteredDoB.Year;
var months = 0;
// Total months
if (dateToday.Month < enteredDoB.Month)
{
months = 12 - dateToday.Month + enteredDoB.Month;
}
else
{
months = enteredDoB.Month - dateToday.Month;
}
if (months > 12)
{
Console.WriteLine($"Years: {years - 1}, Months: {12 - (months - 12)}");
}
else if (months < 0)
{
Console.WriteLine($"Years: {years}, Months: {months - months}");
}
else
{
Console.WriteLine($"Years: {years}, Months: {months}");
}
Console.ReadKey();
Console.ReadKey();
}
private static string AskForDate()
{
var count = 0;
while (count++ < 3)
{
try
{
Console.WriteLine("Enter your date of birth in the format yyyy/mm/dd:");
return DateTime.Parse(Console.ReadLine(), System.Globalization.CultureInfo.InvariantCulture).ToShortDateString();
}
catch (Exception e)
{
Console.WriteLine(e.Message);
//if date was entered incorrectly 3 times, the application should exit..
}
}
Console.WriteLine("\aSorry date still not in correct format - Press any key to exit the application");
Console.ReadKey();
return null;
}
What I made:
I removed your function parseDateString and create a new called AskForDate. This function, like the name says, ask for the date to the user, and inside this function, the date entered is checked if is valid or not.
I believe that is better to check and ask on same function.
If the date entered by user is correct, the date is returned as ToShortDateString. If the date is incorrectly, the function ask two more times, and on third time, a null is returned.
Then, in the EnterDate function, if null is returned from AskForDate function, the program exits.
I also changed some strings interpolations, and removed some variables.

Compare 2 strings of time in C#

So I've got a string 00:00:15:185 which I need to tell is greater than 15 seconds.
Time format is HH:m:ss:FFF
This is clearly longer than 15 seconds but I can't compare it properly.
Current code is this:
value = "00:00:15:185";
if (DateTime.Parse(value) > DateTime.Parse("00:00:15:000"){
//do stuff
}
It's giving exceptions when I run it all the time and the program doesn't work when it should

Your string doesn't represent a time, but an amount of time. We have TimeSpan for that.
var value = "00:00:15:185";
if (TimeSpan.ParseExact(value, #"hh\:mm\:ss\:FFF", CultureInfo.InvariantCulture)
> TimeSpan.FromSeconds(15))
{
//do stuff
}

Another option(apart from #rob 's answer), use DateTime.ParseExact
var value = "00:00:15:185";
if (DateTime.ParseExact(value, "HH:mm:ss:fff", CultureInfo.InvariantCulture) >
DateTime.ParseExact("00:00:15:000", "HH:mm:ss:fff", CultureInfo.InvariantCulture))
{
// logic here.
}

DateTime time = DateTime.Now;
String result = time.ToString("HH:mm ");
DateTime firstTimr = DateTime.ParseExact(reader["shift_start_time"].ToString(), "HH:mm:tt", null);
String firstTimr1 = firstTimr.ToString("HH:mm ");
DateTime lastTime = DateTime.ParseExact(reader["Shift_last_time"].ToString(), "HH:mm:tt", null);
String lastTime1 = lastTime.ToString("HH:mm ");
if (DateTime.Parse(result) >= DateTime.Parse(firstTimr1) && (DateTime.Parse(result) <= DateTime.Parse(lastTime1)))
{
`enter code here` MessageBox.Show("First Shit");
}

How to set date to anything but the future?

I'm writing a program where the user has to enter a date. My questions are:
How can I set the date to today and the past but NOT the future?
How can I set the date to non-US format, i.e. dd/mm/yyyy, so the compiler reads the middle value as month?
This is what my code looks like:
static DateTime date;
and a method like this...
public static void EnterDates()
{
for (int i = 0; i < days; i++)
{
Console.Write("Enter the date (dd/mm/yyyy): ");
date = DateTime.Parse(Console.ReadLine());
centers[k].dates[i] = date;
Console.WriteLine("Day " + centers[k].dates[i]);
Console.Write("Number of movie screenings: ");
movieScreen = Convert.ToInt32(Console.ReadLine());
centers[k].movieScreen[i] = movieScreen;
Console.Write("Total number of customers: ");
customers = Convert.ToInt32(Console.ReadLine());
centers[k].customers[i] = customers;
centers[k].revenue[i] = movieScreen * customers * (centers[k].Price * 1.13);
centers[k].totalRevenue += centers[k].revenue[i];

How can I set the date to today and the past but NOT the future?
Based on what you currently have, you can add a validation after the user enters the date and compare it to DateTime.Now
if(date < DateTime.Now)
//valid
else
//invalid
How can I set the date to non-US format, i.e. dd/mm/yyyy, so the
compiler reads the middle value as month?
You could use DateTime.ParseExact
date = DateTime.ParseExact(Console.ReadLine(), "dd/MM/yyyy", CultureInfo.InvariantCulture)

How to get the day name from a selected date?

I have this : Datetime.Now(); or 23/10/2009
I want this : Friday
For local date-time (GMT-5) and using Gregorian calendar.

//default locale
System.DateTime.Now.DayOfWeek.ToString();
//localized version
System.DateTime.Now.ToString("dddd");
To make the answer more complete:
DayOfWeek MSDN article
If localization is important, you should use the "dddd" string format as Fredrik pointed out - MSDN "dddd" format article

If you want to know the day of the week for your code to do something with it, DateTime.Now.DayOfWeek will do the job.
If you want to display the day of week to the user, DateTime.Now.ToString("dddd") will give you the localized day name, according to the current culture (MSDN info on the "dddd" format string).

System.Threading.Thread.CurrentThread.CurrentUICulture.DateTimeFormat.GetDayName(System.DateTime.Now.DayOfWeek)
or
System.Threading.Thread.CurrentThread.CurrentUICulture.DateTimeFormat.GetDayName(DateTime.Parse("23/10/2009").DayOfWeek)

DateTime.Now.DayOfWeek quite easy to guess actually.
for any given date:
DateTime dt = //....
DayOfWeek dow = dt.DayOfWeek; //enum
string str = dow.ToString(); //string

Here is more simple
DateTime dt;
string yourdate = dt.DayOfWeek.ToString()
better than declare redundant DayOfWeek

DateTime now = DateTime.Now
string s = now.DayOfWeek.ToString();

try this:
DateTime.Now.DayOfWeek

You're looking for the DayOfWeek property.
Here's the msdn article.

What about if we use String.Format here
DateTime today = DateTime.Today;
String.Format("{0:dd-MM}, {1:dddd}", today, today) //In dd-MM format
String.Format("{0:MM-dd}, {1:dddd}", today, today) //In MM-dd format

(DateTime.Parse((Eval("date").ToString()))).DayOfWeek.ToString()
at the place of Eval("date"),you can use any date...get name of day

I use this Extension Method:
public static string GetDayName(this DateTime date)
{
string _ret = string.Empty; //Only for .NET Framework 4++
var culture = new System.Globalization.CultureInfo("es-419"); //<- 'es-419' = Spanish (Latin America), 'en-US' = English (United States)
_ret = culture.DateTimeFormat.GetDayName(date.DayOfWeek); //<- Get the Name
_ret = culture.TextInfo.ToTitleCase(_ret.ToLower()); //<- Convert to Capital title
return _ret;
}

Random Rnd = new Random();
RandomDates Rdate = new RandomDates();
PaymentDetails Payd = new PaymentDetails();
DayOfWeek strDay = DateTime.Today.DayOfWeek;
var dateTime = DateTime.Now;
var dateValue2 = dateTime.ToString(#"MM\/dd\/yyyy");
StepDescription = "Fill MatterInformation. ";
Console.Write(" Input the Day : ");
dt = Convert.ToInt32(Console.ReadLine());
Console.Write(" Input the Month : ");
mn = Convert.ToInt32(Console.ReadLine());
Console.Write(" Input the Year : ");
yr = Convert.ToInt32(Console.ReadLine());
DateTime d = new DateTime(2021, 04, yr);
var culture = System.Threading.Thread.CurrentThread.CurrentCulture;
var diff = d.DayOfWeek - culture.DateTimeFormat.FirstDayOfWeek;
if (diff < 0)
diff += 7;
var x = d.AddDays(-diff).Date;
dateTime = DateTime.Now;
dateValue2 = dateTime.ToString(#"MM\/dd\/yyyy");
Console.WriteLine($"Date Value: {dateValue2}");
// strDay =
}
if (!strDay.Equals("Sunday") | !strDay.Equals("Saturday"))
{
Console.WriteLine("___________________OK____________________________________________");
// string NotificateionDate = Rdate.DateWithin_PastDays(Rnd.Next(30, 260)).ToString(#"MM\/dd\/yyyy");
// CustomLibrary.seWaitUntilElementIsVisible(10, NotiFiedDateTab.Actions.seGetLocator(), "NotiFiedDateTab");
NotiFiedDateTab.Actions.Set(ControlPropertyNames.Text, dateValue2);
}
else
{
Console.WriteLine("_________________________NOT______________________________________");
if (strDay.Equals("Sunday"))
{
dateTime = dateTime.AddDays(-2);
dateValue2 = dateTime.ToString(#"MM\/dd\/yyyy");
NotiFiedDateTab.Actions.Set(ControlPropertyNames.Text, dateValue2);
}
else if (strDay.Equals("Saturday"))
{
dateTime = dateTime.AddDays(-1);
dateValue2 = dateTime.ToString(#"MM\/dd\/yyyy");
NotiFiedDateTab.Actions.Set(ControlPropertyNames.Text, dateValue2);
}
}
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace GuessTheDay
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Enter the Day Number ");
int day = int.Parse(Console.ReadLine());
Console.WriteLine(" Enter The Month");
int month = int.Parse(Console.ReadLine());
Console.WriteLine("Enter Year ");
int year = int.Parse(Console.ReadLine());
DateTime mydate = new DateTime(year,month,day);
string formatteddate = string.Format("{0:dddd}", mydate);
Console.WriteLine("The day should be " + formatteddate);
}
}
}