If I have a DateTime which is, for example, 2012-05-24, what is the quickest way to convert it to a date which is the last day of that month (2012-05-31).
Well you can use:
DateTime date = ...;
var endOfMonth = new DateTime(date.Year, date.Month,
DateTime.DaysInMonth(date.Year, date.Month));
Note that that will create a DateTime with a Kind of Unspecified. You should consider what Kind you really want. (Or use my Noda Time library, where you'd use a LocalDate instead.)
Here's some extension methods I use:
public static class DateTimeExtensionMethods
{
public static DateTime StartOfMonth(this DateTime date)
{
return new DateTime(date.Year, date.Month, 1);
}
public static DateTime EndOfMonth(this DateTime date)
{
return date.StartOfMonth().AddMonths(1).AddSeconds(-1);
}
}
Note that in my case I'm using them for SQL queries, so I want it to be up to the last second of the last day of the month.
Based on comments, yes, if you want just want the date and not time, you could use:
public static DateTime EndOfMonth(this DateTime date)
{
return date.StartOfMonth().AddMonths(1).AddDays(-1);
}
Or just use the Date property of the result to just get the date portion, then it satisfies both cases depending how you use it.
Try this
DateTime dt = DateTime.Parse("2012-05-24");
DateTime lastDate = new DateTime(dt.Year, dt.Month, DateTime.DaysInMonth(dt.Year, dt.Month));
Try this
DateTime date = new DateTime(2012, 05, 24);
DateTime endOfMonth = new DateTime(date.Year, date.Month, DateTime.DaysInMonth(date.Year, date.Month));
Output: 5/31/2012 12:00:00 AM
You can then modify this to your required format.
Related
I have a function which is already compact, i wanted to know if there was better (like a DateTime functionality already included).
Currently i use this:
DateTime today = DateTime.Now;
DateTime tomorrow = new DateTime(today.Year, today.Month, today.Day, 0, 0, 0).AddDays(1);
double remaining = (tomorrow - today).TotalMilliseconds;
Thank for reading.
You can simplify the tomorrow value by just doing this and taking the benefit of DateTime.Today:
DateTime tomorrow = DateTime.Today.AddDays(1);
So your code will be easy to read:
DateTime today = DateTime.Now;
DateTime tomorrow = DateTime.Today.AddDays(1);
double remaining = (tomorrow - today).TotalMilliseconds;
You can create extension for DateTime
public static class DateExtensions
{
public static double GetNextDayRemainingMs(this DateTime dateTime)
{
return (dateTime.AddDays(1).Date - dateTime).TotalMilliseconds;
}
}
Usage
DateTime.Now.GetNextDayRemainingMs();
You can try following code
(DateTime.Today.AddDays(1)-DateTime.Now).TotalMilliseconds
Instead of defining instance for tomorrow variable you can use .AddDate(1).Date property
.AddDate(1) will add one day to DateTime.Now and .Date property
will give you only date and sets time to 00.
DateTime today = DateTime.Now;
double remaining = (today.AddDate(1).Date - today).TotalMilliseconds;
Or (Elegant way)
You can use Today property of DateTime.
An object that is set to today's date, with the time component set to
00:00:00.
double remaining = (DateTime.Today.AddDays(1)-DateTime.Now).TotalMilliseconds
I have dateTime = 3/25/2020 1:25:46 PM
Can I reset time to zero? 3/25/2020 00:00:00
Here is a demo. In this case dateTime is 3/25/2020 12:00:00 AM
class Program
{
static void Main(string[] args)
{
var datetime = DateTime.Now;
datetime = ResetTimeToStartOfDay(datetime);
Console.WriteLine(datetime);
Console.ReadLine();
}
public static DateTime ResetTimeToStartOfDay(DateTime dateTime)
{
return new DateTime(
dateTime.Year,
dateTime.Month,
dateTime.Day,
0, 0, 0, 0);
}
}
How to reset the date to the beginning of the day?
more simply:
return dateTime.Date;
But note that in the specific case of DateTime.Now you could just use DateTime.Today instead.
How to reset the date to the beginning of the day?
You already are in your method ResetTimeToStartOfDay although there is an easier way to do it with dateTime.Date which is functionally equivalent.
So your question now becomes:
Why do you see 3/25/2020 12:00:00 AM instead of 3/25/2020 00:00:00 when Console.WriteLine(datetime); is called.
When you call ToString() on the DateTime instance, which happens implicitly in Console.WriteLine(datetime);, the displayed format matches the culture of the current thread which then displays the time using AM/PM. If you want to display the date as 3/25/2020 00:00:00 then call ToString() explicitly and pass a format string like M/d/yyyy HH:mm:ss
Console.WriteLine(datetime.ToString("M/d/yyyy HH:mm:ss"));
See also Custom date and time format strings
Try:
public static DateTime SetTimeToZero(DateTime YourDate)
{
return new DateTime(YourDate.Year, YourDate.Month, YourDate.Day, 0, 0, 0);
}
or you can create an ExtensionMethod and use inside your project:
public static DateTime SetTimeToZero(this DateTime YourDate)
{
return new DateTime(YourDate.Year, YourDate.Month, YourDate.Day, 0, 0, 0);
}
How to use ExtensionMethod:
yourDatetime.SetTimeToZero(date);
I am converting a datetime value to Indian Standard Time using the below code:
public DateTime GetdatetimedetailsinIST(DateTime datetimeinfo, String timeoffsetvalue)
{
string offset= timeoffsetvalue;
string timeZoneFormat = Convert.ToString("India Standard Time");
string strIndianTimezone = timeZoneFormat;
TimeZoneInfo tzinfoIndian = TimeZoneInfo.FindSystemTimeZoneById(strIndianTimezone);
DateTime dtDateTime = datetimeinfo.AddMinutes(Convert.ToInt32(offset));//ToUniversalTime();
dtDateTime = TimeZoneInfo.ConvertTimeFromUtc(dtDateTime, tzinfoIndian);
return dtDateTime;
}
Now I am calling GetdatetimedetailsinIST(5/6/2014 8:00:00 AM,"240");
and it will reurn Indian Time 5/6/2014 5:30:00 PM.
Now I want to get back the 5/6/2014 8:00:00 AM for another scenario by using value 5/6/2014 5:30:00 PM.
What are the changes need to do in the above function?
Please help.
howeverCould you add a string timeZoneToConvertTo parameter to your convert method?
public static DateTime DateTimeConvert(DateTime nonConvertedDateTime, string timeoffsetvalue, string timeZoneToConvertTo)
{
TimeZoneInfo tzinfo = TimeZoneInfo.FindSystemTimeZoneById(timeZoneToConvertTo);
DateTime dtDateTime = nonConvertedDateTime.AddMinutes(Convert.ToInt32(timeoffsetvalue));
dtDateTime = TimeZoneInfo.ConvertTimeFromUtc(dtDateTime, tzinfo);
return dtDateTime;
}
Console.WriteLine(DateTimeConvert(new DateTime(2014, 5, 6, 8, 00, 00), "240", "India Standard Time").ToString());
Console.WriteLine(DateTimeConvert(new DateTime(2014, 5, 6, 8, 00, 00), "240", "Central Standard Time").ToString());
You still need to handle any exceptions resulting from an inability to find the timezone.
I don't understand why you want an offset instead of using the ToUniversal() extension, however, that is your choice.
Adding minutes manually is seldom required or recommended. Also, there are a lot of unnecessary strings floating around your method. Consider the following instead:
public static DateTime ConvertToIndiaTime(DateTime dateTime, int offsetMinutes)
{
// Create a DateTimeOffset from the input values.
// This assumes positive offset values are *WEST* of UTC,
// such as if it came from the getTimeZoneOffset function of
// JavaScript's Date object.
TimeSpan offset = TimeSpan.FromMinutes(-offsetMinutes);
DateTimeOffset dto = new DateTimeOffset(dateTime, offset);
// Convert the DateTimeOffset to the desired time zone
DateTimeOffset converted =
TimeZoneInfo.ConvertTimeBySystemTimeZoneId(dto, "Indian Standard Time");
// Return the DateTime portion, representing the local time in India.
return converted.DateTime;
}
You would call it like this:
// get a DateTime object
DateTime dt = DateTime.ParseExact("5/6/2014 8:00:00 AM",
"M/d/yyyy h:mm:ss tt",
CultureInfo.InvariantCulture);
// get the offset as an integer
int offsetMinutes = 240;
// call the conversion method
DateTime indiaTime = ConvertToIndiaTime(dt, offsetMinutes);
Your method seems to combine two separate DateTime operations into one - hence it's not easy for you to reverse the operation. How about the following structure:
private static readonly TimeZoneInfo IstTimeZone =
TimeZoneInfo.FindSystemTimeZoneById("India Standard Time");
public static DateTime ConvertDateTimeUtcToIst(DateTime toConvert)
{
return TimeZoneInfo.ConvertTimeFromUtc(toConvert, IstTimeZone);
}
public static DateTime ConvertDateTimeIstToUtc(DateTime toConvert)
{
return TimeZoneInfo.ConvertTimeToUtc(toConvert, IstTimeZone);
}
Usage:
var converted = ConvertDateTimeUtcToIst(DateTime.Parse("5/6/2014 8:00:00 AM"))
.AddMinutes(240);
var reverted = ConvertDateTimeIstToUtc(converted).AddMinutes(-240);
Or if you absolutely need to have it in one method:
public static DateTime ConvertDateTimeUtcToIst(
DateTime toConvert, int offset = 0)
{
return TimeZoneInfo.ConvertTimeFromUtc(toConvert, IstTimeZone)
.AddMinutes(offset);
}
public static DateTime ConvertDateTimeIstToUtc(
DateTime toConvert, int offset = 0)
{
return TimeZoneInfo.ConvertTimeToUtc(toConvert, IstTimeZone)
.AddMinutes(offset);
}
Usage:
var converted = ConvertDateTimeUtcToIst(
DateTime.Parse("5/6/2014 8:00:00 AM"), 240);
var reverted = ConvertDateTimeIstToUtc(converted, -240);
I have two DateTime fields that I'd like to automatically fill so that the PeriodFrom field is set to 7 days ago and the PeriodTo field is set to today's date.
At present I have them set up so that the PeriodFrom is set to the first day of the month with the following code:
PeriodFrom = DateTime.Now.FirstDayOfMonth();
PeriodTo = DateTime.Today;
where FirstDayOfMonth() is the extension method:
public static DateTime FirstDayOfMonth(this DateTime dateTime)
{
return new DateTime(dateTime.Year, dateTime.Month, 1);
}
Is there a quick extension method that I could write to set the date to exactly 1 week ago?
public static DateTime OneWeekAgo(this DateTime dateTime)
{
return dateTime.AddDays(-7);
}
Usage, as you already understand, like this:
PeriodFrom = DateTime.Now.OneWeekAgo();
PeriodTo = DateTime.Today;
I am retrieving data from an iSeries where there is a separate date and time fields. I want to join them into a DateTime field in my C# project. I don't see a way to add just a time to a DateTime field. How would you suggest accomplishing this?
You can do this quite easily:
DateTime dateOnly;
DateTime timeOnly;
...
DateTime combined = dateOnly.Date.Add(timeOnly.TimeOfDay);
TimeOfDay returns a TimeSpan, which you then add to the date.
Edit (thanks to commenters below) - to be safe, use dateOnly.Date to ensure the date part only.
How are they being stored? Assuming that the date portion is being stored as a DateTime of midnight of the day in question and the time is a TimeSpan, you can just add them.
DateTime date = ...;
TimeSpan time = ...;
DateTime result = date + time;
You could easily construct a TimeSpan from your "time" field.
Once you have that, just do:
TimeSpan time = GetTimeFieldData();
dateField = dateField.Add(time);
Datetime date = new DateTime(Date1.Year, Date1.Month, Date1.Day, Time1.Hour, Time1.Minute, Time1.Second);
You can add a TimeSpan to a DateTime and write something like this.
// inside consuming function
ISeriesObject obj = getMyObject();
DateTime dt = getDate(obj) + getTime(obj);
private DateTime getDate(ISeriesObject obj)
{
//return a DateTime
}
private TimeSpan getTime(ISeriesObject obj)
{
//return a TimeSpan
}
My answer addresses joining two objects of DateOnly and TimeOnly in .NET 6:
DateOnly orderDate = ...
TimeOnly orderTime = ...
DateTime orderDateTime = orderDate.ToDateTime(orderTime);
This should do:
var output = date.Date + time.TimeOfDay;
or
var output = new DateTime(date.Year, date.Month, date.Day,
time.Hour, time.Minute, time.Second);
suppose that both variable date and time are both of Type DateTime
Note that adding the time to the date is not your biggest problem here. As #Reed Copsey mentioned, you just create a DateTime from the date and then .Add the time.
However, you need to make sure that the iSeries date and time (a Unix time most probably) are in the same representation as the .Net representation. Thus, you most probably need to convert it by adding it to a Jan 1, 1970 DateTime as well.
Cant you simply format the date part and time part as separate strings, then join them together? Then you can parse the string back to a DateTime object