I need to process the CreationTime I retrieve from the PDF's metadata and compare it to DataTime format.
string path = e.Row.Cells[1].Text;
var pdfReader = new PdfReader(path);
var CreatedDate = pdfReader.Info["CreationDate"];
e.Row.Cells[13].Text = Convert.ToString(CreatedDate);
This returns a Date-Time-String like:
D:20150710080410
D:20150209075651+01'00'
and to compare:
DateTime Created = Convert.ToDateTime(CreatedDate);
DateTime Compare = Convert.ToDateTime(e.Row.Cells[14].Text);
if (Compare > Created)
{
e.Row.Cells[15].Text = "actualizar";
}
Martin
I really needed a solution for this, BBL Admin 's Comment on writing your own function turned out to be my way out.
From this [this itex support link][1] I was able to get the intepratation of the pdfDate format as D:YYYYMMDDHHmmSSOHH'mm'
Next thing I needed to know is the supportade date formats in c# that I may Parse using DateTime.Parse() from [this c-sharpcorner artical][2] and the most ideal for me was "yyyy’-‘MM’-‘dd’T’HH’:’mm’:’ss"
Having known the input I get and the format I can parse, I created the function below to construct the date, basically getting parts from the pdfDate and building parts for the 'parsable' date string...
private DateTime CreateDateTime(string date) //use the pdfDate as parameter to the date argument
{
string dateStr = date.Remove(0, 2).Remove(14, 6); //Remove D: & OHH'mm
string tmpDateStr = dateStr.Substring(0, 4) //Get year i.e yyyy
+ "-" + dateStr.Substring(4, 2) // Get month i.e mm & prepend - (hyphen)
+ "-" + dateStr.Substring(6, 2) // Get day i.e dd & prepend -
+ "T" + dateStr.Substring(8, 2) // Get hour and prepend T
+ ":" + dateStr.Substring(10, 2) // Get minutes and prepend :
+ ":" + dateStr.Substring(12, 2); //Get seconds and prepend :
return DateTime.Parse(tmpDateStr);
}
Well, I hope you found a way at the time of asking, anyone else facing the same challange could try my approach and see if it helps. Nevertheless, question answered.
NB: There could be other/better ways to do it.
[1]: http://itextsupport.com/apidocs/iText7/7.1.0/com/itextpdf/kernel/pdf/PdfDate.html
[2]: https://www.c-sharpcorner.com/blogs/date-and-time-format-in-c-sharp-programming1
If your Date-Time string that you're trying to convert is going to start with "D:" every time, then you might think about adding in a remove function for D:. That's what's probably giving you the exception when you try to convert. Try this:
// Gather the Info
string path = e.Row.Cells[1].Text;
var pdfReader = new PdfReader(path);
var CreatedDate = pdfReader.Info["CreationDate"];
e.Row.Cells[13].Text = Convert.ToString(CreatedDate);
string sCreatedDate = Convert.ToString(CreatedDate).Remove(0, 2)
// Convert and Compare
DateTime Created = Convert.ToDateTime(sCreatedDate);
DateTime Compare = Convert.ToDateTime(e.Row.Cells[14].Text);
if (Compare > Created)
{
e.Row.Cells[15].Text = "actualizar";
}
You don't have to create sCreatedDate, but it's a little bit cleaner to view it that way. You could also convert CreatedDate.ToString().Remove(0,2) when you do the datetime convert:
DateTime Created = Convert.ToDateTime(CreatedDate.ToString().Remove(0,2));
Hope this helps.
I have an Sql database which contains a date field.
I use Dapper to update the database as follows:
const string sql = "UPDATE AdminDb.Users " +
"SET IsLoggedOn = 1, LastLoggedOn = #LastLoggedOn " +
"WHERE Username = #username";
var date = DateTime.UtcNow;
DatabaseConnectionBase.DatabaseConnection.Execute(sql, new { username, LastLoggedOn = date });
I am finding to my great annoyance when breaking before the actual update, the date variable reads 30/3/2015 9:32:54 however when I run the update the database saves the date as 30/3/2015 10:32:54
As the UK yesterday changed from GMT to BST (UTC +1) I am sure that the database seems to be trying to compensate for this as this issue never came up before.
I thought I had averted this sort of issue by using the DateTime.UtcNow property to save my date.
This is causing serious issues when validating users.
I am sure it is not my code as the date is correct going into the Dapper Execute method.
I can't see why Dapper would try to compensate as most developers would be screaming at such functionality
Which leads me to the conclusion that it must be something in Sqlite that is causing this issue. Perhaps there is a pragma I need to run?
As per a suggestion from another site I tried formatting the date as follows:
var date = DateTime.UtcNow.ToString("o");
The intention being to force the date into ISO-8601 format but I had no luck with that.
Has anyone got any ideas?
Thomas Levesque has the solution here:
// You just need to specify DateTimeKind=Utc in your connection string:
string connectionString = #"Data Source=D:\tmp\testSQLiteDate.db;DateTimeKind=Utc";
This happened to me too.
What I did was serialize the datetime to a string myself before adding it as a parameter.
internal const string DateTimeFormat = "yyyy-MM-dd HH:mm:ss";
cmd.Parameters.Add("#Threshold", DbType.DateTime).Value = threshold.ToString(DateTimeFormat);
If you do the same thing with pure ADO.NET, does the same thing happen? I wonder if this is a database thing or a provider thing, rather than a library thing. Dapper has to ToLocalTime() or ToUniversalTime() calls - it passes the time through unaltered. On SQL Server, the following works fine in a BST setting:
public void SO29343103_UtcDates()
{
const string sql = "select #date";
var date = DateTime.UtcNow;
var returned = connection.Query<DateTime>(sql, new { date }).Single();
var delta = returned - date;
Assert.IsTrue(delta.TotalMilliseconds >= -1 && delta.TotalMilliseconds <= 1);
}
I pick up data which includes some date columns. Date returned from database is in UTC format. I feed this data to report viewer and want to show the date in local format, considering daylight saving.
I can do that from server side but I want the conversion to be according to the client machine timezone.
Is there any way to do it ?
Is your client a web page or a .NET app? If it is a .NET app you could do it like this. Firstly send your client timezone to your server like so:
string clientTimeZone = TimeZoneInfo.Local.ToSerializedString();
Then on your server:
var clientTimeZoneInfo = TimeZoneInfo.FromSerializedString(clientTimeZone);
var localDateTime = TimeZoneInfo.ConvertTimeFromUtc(utcDateTime, clientTimeZoneInfo);
If this is a webapp use this javascript to send the offset to the server:
var timeNow = new Date();
var timezone = timeNow.getTimezoneOffset() / 60 * (-1);
Then on your server:
string clientTimeZoneOffset = "8";
var clientTimeZoneInfo = TimeZoneInfo.CreateCustomTimeZone("client", new TimeSpan(0, Int32.Parse(clientTimeZoneOffset), 0, 0),
"client", "client");
var utcDateTime = DateTime.UtcNow;
DateTime localDateTime = TimeZoneInfo.ConvertTimeFromUtc(utcDateTime, clientTimeZoneInfo);
I am building an application in MVC3 and when a user comes into my site I want to know that user's timezone. I want to know how to do this in c# not in javaScript?
As has been mentioned, you need your client to tell your ASP.Net server details about which timezone they're in.
Here's an example.
I have an Angular controller, which loads a list of records from my SQL Server database in JSON format. The problem is, the DateTime values in these records are in the UTC timezone, and I want to show the user the date/times in their local timezone.
I determine the user's timezone (in minutes) using the JavaScript "getTimezoneOffset()" function, then append this value to the URL of the JSON service I'm trying to call:
$scope.loadSomeDatabaseRecords = function () {
var d = new Date()
var timezoneOffset = d.getTimezoneOffset();
return $http({
url: '/JSON/LoadSomeJSONRecords.aspx?timezoneOffset=' + timezoneOffset,
method: 'GET',
async: true,
cache: false,
headers: { 'Accept': 'application/json', 'Pragma': 'no-cache' }
}).success(function (data) {
$scope.listScheduleLog = data.Results;
});
}
In my ASP.Net code, I extract the timezoneOffset parameter...
int timezoneOffset = 0;
string timezoneStr = Request["timezoneOffset"];
if (!string.IsNullOrEmpty(timezoneStr))
int.TryParse(timezoneStr, out timezoneOffset);
LoadDatabaseRecords(timezoneOffset);
... and pass it to my function which loads the records from the database.
It's a bit messy as I want to call my C# FromUTCData function on each record from the database, but LINQ to SQL can't combine raw SQL with C# functions.
The solution is to read in the records first, then iterate through them, applying the timezone offset to the DateTime fields in each record.
public var LoadDatabaseRecords(int timezoneOffset)
{
MyDatabaseDataContext dc = new MyDatabaseDataContext();
List<MyDatabaseRecords> ListOfRecords = dc.MyDatabaseRecords.ToList();
var results = (from OneRecord in ListOfRecords
select new
{
ID = OneRecord.Log_ID,
Message = OneRecord.Log_Message,
StartTime = FromUTCData(OneRecord.Log_Start_Time, timezoneOffset),
EndTime = FromUTCData(OneRecord.Log_End_Time, timezoneOffset)
}).ToList();
return results;
}
public static DateTime? FromUTCData(DateTime? dt, int timezoneOffset)
{
// Convert a DateTime (which might be null) from UTC timezone
// into the user's timezone.
if (dt == null)
return null;
DateTime newDate = dt.Value - new TimeSpan(timezoneOffset / 60, timezoneOffset % 60, 0);
return newDate;
}
It works nicely though, and this code is really useful when writing a web service to display date/times to users in different parts of the world.
Right now, I'm writing this article at 11am Zurich time, but if you were reading it in Los Angeles, you'd see that I edited it at 2am (your local time). Using code like this, you can get your webpages to show date times that make sense to international users of your website.
Phew.
Hope this helps.
This isn't possible server side unless you assume it via the users ip address or get the user to set it in some form of a profile. You could get the clients time via javascript.
See here for the javacript solution: Getting the client's timezone in JavaScript
You will need to use both client-side and server-side technologies.
On the client side:
(pick one)
This works in most modern browsers:
Intl.DateTimeFormat().resolvedOptions().timeZone
There is also jsTimeZoneDetect's jstz.determine(), or Moment-Timezone's moment.tz.guess() function for older browsers, thought these libraries are generally only used in older applications.
The result from either will be an IANA time zone identifier, such as America/New_York. Send that result to the server by any means you like.
On the server side:
(pick one)
Using TimeZoneInfo (on. NET 6+ on any OS, or older on non-Windows systems only):
TimeZoneInfo tzi = TimeZoneInfo.FindSystemTimeZoneById("America/New_York");
Using TimeZoneConverter (on any OS):
TimeZoneInfo tzi = TZConvert.GetTimeZoneInfo("America/New_York");
Using NodaTime (on any OS):
DateTimeZone tz = DateTimeZoneProviders.Tzdb["America/New_York"];
I got the same issue , Unfortunately there is no way for the server to know the client timezone .
If you want you can send client timezone as header while making ajax call .
In-case if you want more info on adding the header this post may help how to add header to request : How can I add a custom HTTP header to ajax request with js or jQuery?
new Date().getTimezoneOffset();//gets the timezone offset
If you don't want to add header every time , you can think of setting a cookie since cookie is sent with all httpRequest you can process the cookie to get client timezone on server side . But i don't prefer adding cookies , for the same reason they sent with all http requests.
Thanks.
For Dot Net version 3.5 and higher you can use :
TimeZoneInfo.Local.GetUtcOffset(DateTime.UtcNow);
but for Dot Net lower than version 3.5 you can handle it manually via this way :
first, get Offset from the client and store it in the cookie
function setTimezoneCookie(){
var timezone_cookie = "timezoneoffset";
// if the timezone cookie does not exist create one.
if (!$.cookie(timezone_cookie)) {
// check if the browser supports cookie
var test_cookie = 'test cookie';
$.cookie(test_cookie, true);
// browser supports cookie
if ($.cookie(test_cookie)) {
// delete the test cookie
$.cookie(test_cookie, null);
// create a new cookie
$.cookie(timezone_cookie, new Date().getTimezoneOffset());
// re-load the page
location.reload();
}
}
// if the current timezone and the one stored in cookie are different
// then store the new timezone in the cookie and refresh the page.
else {
var storedOffset = parseInt($.cookie(timezone_cookie));
var currentOffset = new Date().getTimezoneOffset();
// user may have changed the timezone
if (storedOffset !== currentOffset) {
$.cookie(timezone_cookie, new Date().getTimezoneOffset());
location.reload();
}
}
}
after that you can use a cookie in backend code like that :
public static string ToClientTime(this DateTime dt)
{
// read the value from session
var timeOffSet = HttpContext.Current.Session["timezoneoffset"];
if (timeOffSet != null)
{
var offset = int.Parse(timeOffSet.ToString());
dt = dt.AddMinutes(-1 * offset);
return dt.ToString();
}
// if there is no offset in session return the datetime in server timezone
return dt.ToLocalTime().ToString();
}
I know the user asked about a non-javascript solution, but I wanted to post a javascript solution that I came up with. I found some js libraries (jsTimezoneDetect, momentjs), but their output was an IANA code, which didn't seem to help me with getting a TimeZoneInfo object in C#. I borrowed ideas from jsTimezoneDetect. In javascript, I get the BaseUtcOffset and the first day of DST and send to server. The server then converts this to a TimeZoneInfo object.
Right now I don't care if the client Time Zone is chosen as "Pacific Time (US)" or "Baja California" for example, as either will create the correct time conversions (I think). If I find multiple matches, I currently just pick the first found TimeZoneInfo match.
I can then convert my UTC dates from the database to local time:
DateTime clientDate = TimeZoneInfo.ConvertTimeFromUtc(utcDate, timeZoneInfo);
Javascript
// Time zone. Sets two form values:
// tzBaseUtcOffset: minutes from UTC (non-DST)
// tzDstDayOffset: number of days from 1/1/2016 until first day of DST ; 0 = no DST
var form = document.forms[0];
var janOffset = -new Date(2016, 0, 1).getTimezoneOffset(); // Jan
var julOffset = -new Date(2016, 6, 1).getTimezoneOffset(); // Jul
var baseUtcOffset = Math.min(janOffset, julOffset); // non DST offset (winter offset)
form.elements["tzBaseUtcOffset"].value = baseUtcOffset;
// Find first day of DST (from 1/1/2016)
var dstDayOffset = 0;
if (janOffset != julOffset) {
var startDay = janOffset > baseUtcOffset ? 180 : 0; // if southern hemisphere, start 180 days into year
for (var day = startDay; day < 365; day++) if (-new Date(2016, 0, day + 1, 12).getTimezoneOffset() > baseUtcOffset) { dstDayOffset = day; break; } // noon
}
form.elements["tzDstDayOffset"].value = dstDayOffset;
C#
private TimeZoneInfo GetTimeZoneInfo(int baseUtcOffset, int dstDayOffset) {
// Converts client/browser data to TimeZoneInfo
// baseUtcOffset: minutes from UTC (non-DST)
// dstDayOffset: number of days from 1/1/2016 until first day of DST ; 0 = no DST
// Returns first zone info that matches input, or server zone if none found
List<TimeZoneInfo> zoneInfoArray = new List<TimeZoneInfo>(); // hold multiple matches
TimeSpan timeSpan = new TimeSpan(baseUtcOffset / 60, baseUtcOffset % 60, 0);
bool supportsDst = dstDayOffset != 0;
foreach (TimeZoneInfo zoneInfo in TimeZoneInfo.GetSystemTimeZones()) {
if (zoneInfo.BaseUtcOffset.Equals(timeSpan) && zoneInfo.SupportsDaylightSavingTime == supportsDst) {
if (!supportsDst) zoneInfoArray.Add(zoneInfo);
else {
// Has DST. Find first day of DST and test for match with sent value. Day = day offset into year
int foundDay = 0;
DateTime janDate = new DateTime(2016, 1, 1, 12, 0, 0); // noon
int startDay = zoneInfo.IsDaylightSavingTime(janDate) ? 180 : 0; // if southern hemsphere, start 180 days into year
for (int day = startDay; day < 365; day++) if (zoneInfo.IsDaylightSavingTime(janDate.AddDays(day))) { foundDay = day; break; }
if (foundDay == dstDayOffset) zoneInfoArray.Add(zoneInfo);
}
}
}
if (zoneInfoArray.Count == 0) return TimeZoneInfo.Local;
else return zoneInfoArray[0];
}
You can get this information from client to server (any web API call)
var timezoneOffset = new Date().getTimezoneOffset();
With the help of timezoneoffset details you can achieve the same. Here in my case i converted UTC DateTime to my client local datetime in Server side.
DateTime clientDateTime = DateTime.UtcNow - new TimeSpan(timezoneOffset / 60, timezoneOffset % 60, 0);
Click for code example
Take a look at this asp.net c# solution
TimeZoneInfo mytzone = TimeZoneInfo.Local;
System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_TIMEZONE"] ;
I'm using several literals to inject the user's time onto the the page. The values in the HTML are the UTC times.
var TheDay = parseInt($('#UserDayToday').html(), 10);
var TheMonth = parseInt($('#UserMonthToday').html(), 10);
var TheYear = parseInt($('#UserYearToday').html(), 10);
var TheHours = parseInt($('#UserTimeStampHours').html(), 10);
var TheMinutes = parseInt($('#UserTimeStampMinutes').html(), 10);
Now I want to build a time stamp with that time so I tried this:
var TheDateToday = new Date();
TheDateToday.setUTCFullYear(TheYear, TheMonth, TheDay);
TheDateToday.setUTCHours(TheHours, TheMinutes, 0, 0);
alert(TheDateToday);
When the alert comes on, it gives me the time with his timezone shift added. How can I just have the the UTC time. I know I can get it from the browser but I want to get the UTC time built from the data sent from the server, not retrieved from the user's machine by the browser.
Thanks
You are displaying the date in local time. Use the toUTCString method instead of the implicit toString method:
alert(TheDateToday.toUTCString());