My task: I am going to run a contest world wide at my website. A problem setter will set problems from a specific area of the world setting a time and date of starting time of the contest. I have to show that time correctly all over the world so the the contest starts at a time everywhere of the world.
My Idea : I planed to get the time from the problem setter of his time zone using server site language like php time(), & will store to database converting to timezone= zero (0). And who are going to attend the contest I'll just add hour(s) of that time zone with my database time.
Need help: I have no Idea how to convert that timestamps to timezone 'zero', even how can I get the ±hour(s) of current timezone?
Thank you...
Step 1:
Let the user choose his timezone. You could fill a dropdown with values from this site: http://php.net/manual/en/timezones.php
Step 2:
Convert the timezone to servertime
$timezone_client = new DateTimeZone('America/Denver');
$timezone_server = new DateTimeZone('Pacific/Nauru');
$datetime = new DateTime('2013-01-25 12:00:00', timezone_client);
$datetime->setTimezone($timezone_server);
echo $datetime->format('Y-m-d H:i:s');
Timezone 0 = "UTC" (sometimes called GMT)
Your system / language will have a Timezone class, which provides difference to GMT/UTC
Related
How do I get a list of "time zones" from NodaTime such that I can make a UI like the below for my users to choose from?
I want to show the UTC offset and then the appropriate cities/countries/locations. It doesn't need to be exactly like the below, but you know, something close.
DateTimeZone doesn't have a name property, and ToString()ing produces duplicates (from the list of Ids from IDateTimeZoneProvider).
I see you can go from ~countries to zones, with TzdbDateTimeZoneSource.Default.ZoneLocations, but thats also not exactly what I'm looking for. I can see how I can cobble these two data sources together, but this feels like a solved problem I shouldn't be reinventing.
Noda Time doesn't currently provide user-oriented strings for time zones, no.
The best source of data for that is CLDR. We have a long-standing issue for this, but unfortunately it's fundamentally tricky. At some point I'd like to get back to it, but I haven't found time yet :(
You can use the Onism.Cldr project to access CLDR data. You'll need to understand how the CLDR data works in two respects though:
The time zone data structures such as metazones
The text data structures that allow you to get a particular string resource in the user's chosen language
Apologies that the answer at the moment is really just "No, there's nothing out of the box" - but that's the reality :(
You can get a list of display names and their corresponding IANA time zone ids, suitable for building a dropdown in the way you described, using my TimeZoneNames library. The resulting IDs are compatible with NodaTime's TZDB provider.
// You can either hardcode the language (ex: "en-US"), or get it from .NET globalization:
var languageCode = CultureInfo.CurrentUICulture.Name;
// Then get the names, as a list of key/value pairs
var list = TZNames.GetDisplayNames(languageCode, useIanaZoneIds: true);
// Use them as you wish. For example:
foreach (var name in list)
{
Console.WriteLine($"{name.Key} = \"{name.Value}\"");
}
Output (truncated):
Etc/GMT+12 = "(UTC-12:00) International Date Line West"
Etc/GMT+11 = "(UTC-11:00) Coordinated Universal Time-11"
America/Adak = "(UTC-10:00) Aleutian Islands"
Pacific/Honolulu = "(UTC-10:00) Hawaii"
Pacific/Marquesas = "(UTC-09:30) Marquesas Islands"
America/Anchorage = "(UTC-09:00) Alaska"
Etc/GMT+9 = "(UTC-09:00) Coordinated Universal Time-09"
America/Tijuana = "(UTC-08:00) Baja California"
Etc/GMT+8 = "(UTC-08:00) Coordinated Universal Time-08"
America/Los_Angeles = "(UTC-08:00) Pacific Time (US & Canada)"
America/Phoenix = "(UTC-07:00) Arizona"
America/Chihuahua = "(UTC-07:00) Chihuahua, La Paz, Mazatlan"
America/Denver = "(UTC-07:00) Mountain Time (US & Canada)"
America/Guatemala = "(UTC-06:00) Central America"
America/Chicago = "(UTC-06:00) Central Time (US & Canada)"
Pacific/Easter = "(UTC-06:00) Easter Island"
...
The display names are sourced from Windows language packs. The IDs are translated from Windows to IANA through CLDR. If you want Windows IDs instead, you can set useIanaZoneIds to false (or omit it).
See also Methods for listing time zones and the Acknowledgements in the TimeZoneNames docs.
You can consider using GeoTimeZone Nuget Package to get the IANA timezone id by location i.e latitude and longitude for example
// using coordinates for a place in London use GeoTimeZone Library
string tz = GeoTimeZone.TimeZoneLookup.GetTimeZone(50.4372, -3.5559).Result; // Europe/London
DateTimeZone dateTimeZone = DateTimeZoneProviders.Tzdb.GetZoneOrNull(tz);
//You can get the UTC timeoffset at any instant possibly like this
Offset offset = dateTimeZone
.GetUtcOffset(SystemClock.Instance.GetCurrentInstant());
Console.WriteLine(offset); //+01
Consider the following case. I have a Voucher model with a datetime activation_due_date field and user model that has up-to-date information about his location (timezone, UTC offset).
I want to check if he requests voucher activation before due date in any of available time zones. For instance, If a due date is set to 28.08.2018 23:59 UTC
I want my scope before_activation_due to check if he requests something before 28.08.2018 - 23:59 in his current time zone so my due date is not something fixed - it depends on users location - In one place it can be after due date and in the other before.
I have tried the following approach.
models/voucher.rb
scope :before_activation_due, lambda { |user|
where('activation_due_date > ? ', Time.current.to_utc + user.utc_offset)
}
My questions are:
Is this a right approach? If not, what is the proper way for dealing with such cases?
How to test such a scope? The current timestamp is probably taken from a database server when comparing datetimes during query execution so I am not sure how to mock it in my specs.
Thanks in advance.
You can store just the timezone of the user, not the offset, then do:
where('activation_due_date > ? ', Time.now.utc.in_time_zone(user.timezone))
where timezone is any valid timezone shown in
rake time:zones
That'd be the more rails-y way to do things at least. But I don't think storing an offset then manually adding it to the time is a bad approach.
To test this, you can manually insert any date you want in to your database. Then you can use a gem like https://github.com/travisjeffery/timecop to travel in time to that point, and test your scope:
Voucher.create(activation_due_date: '2018-01-02 00:00:00')
format = '%Y-%m-%d %H:%M:%S %Z'
time = DateTime.strptime("2018-01-02 00:00:00 Central Time (US & Canada)",format)
Timecop.travel(time)
Voucher.before_activation_due.all ...
One approach is to convert the activation_due_date into the timezone of the user. As you say "my due date is not something fixed - it depends on users location".
To do this as a scope the easiest thing would be to use your databases timezone functions. This depends on which database you are using, but in PostgreSQL it will be something like:-
where('activation_due_date AT TIME ZONE ? > NOW() ', user.timezone)
An even simpler way would be to do a string comparison
where('to_char(activation_due_date, 'YYYYMMDDHH24MISS') > ?', Time.current.in_time_zone(user.timezone).strftime('%Y%m%d%H%M%S');
In this case we are saying what is the time on the wall for the user, and is it less than time in the database (which is "stored" in UTC).
I am using postrges db.
My domain has a date field:
java.util.Date requestedDate;
I am trying to search by date in my controller:
eq ("requestedDate", requestedDate)
This works fine, but the problem is that date and time has to be exactly matching for this. But in application the user will only enter the date to search items (like give me all requests which are made on 2014-02-05 and the browser application will add the current time to the request). So the comparison fails because the user entered time is different from the time during creation of the request.
I tried 'like' but it throws error.
How to compare only date part ?
You could do something like this:
Date now = new Date()
now.clearTime()
def results = Meeting.withCriteria {
between('date', now, now+1)
}
So this strips off the time portion of the current date, and then does a 'between' query (between midnight just gone and midnight 24 hours later).
Still it looks like there is no convenient way to realize this.
You need a small detour by computing the start of the day and the end of the day and use the between operator.
EDIT
I just saw now rcgeorge23 gave you the right example for doing this.
Is this possible to evaluate the duration between a specified date on a form of a workflow, and the system date ? that what I want to do, in order to show (if this possible too) a short message if 1 day occurs since the specified date above, forbidding the transition of the status Closed to Reopened...
Thanks a lot,
Christophe
I think the Script Runner has a validator that does something like this but I can't find it. Then you could write a post function with the Script Runner. Otherwise it's back to creating a custom validator, as described in my book Practical JIRA Plugins (O'Reilly)
You can use the ScriptRunner plugin in addition with the following script in the validator section for the Reopened transition:
Date now = new Date()
Date cfDate = new Date(cfValues['YourCustomField'].getTime())
new Date(now.getYear(), now.getMonth(), now.getDate()).compareTo(cfDate) <= 0
Replace YourCustomField with the name of your custom field. This will ensure that the transition will check whether the current date is beyond the date set in the custom field, and blocks it if it is.
First of all, thank you for your answer.
It works to allow transition when dates are similar, but my purpose was modified by my responsible. He would like to allow the transition if dates are similar or if the duration between them is only 1 day or less.
Example :
System date is 09/07/2013 (Paris)
My date (dd/mm/yyyy format) Transition allowed Why
07/07/2013 NO my date is former to system date
08/07/2013 NO my date is former to system date
09/07/2013 YES my date and system date equals
10/07/2013 YES only 1 day occur between 2 dates
11/07/2013 NO 2 days occur between 2 dates
Here is the code I wrote in order to do that, but it does'nt work (maybe a Java syntax error?) :
Date now = new Date()
Date cfDate = new Date(cfValues['Date de clôture réelle de la demande'].getTime())
new Boolean(((now.getTime() - cfDate) / 86400000) <= 1) && (now.getTime() >= cfDate ))
Excuse me for my english. I'm french, and I try to improve my English.
Thanks a lot.
I am trying to get the time of other GMT value by using
Calendar c1 = Calendar.getInstance(TimeZone.getTimeZone(gmt));
but how can i get the DST time at that time zone.
The TimeZone class provides a getDSTSavings() method for a specific TimeZone Object. (JavaDoc: "Returns the amount of time to be added to local standard time to get local wall clock time.")
The Calendar interface provides two getOffset() methods, which let you find out the offset from UTC. (JavaDoc: "Returns the offset of this time zone from UTC at the specified date. If Daylight Saving Time is in effect at the specified date, the offset value is adjusted with the amount of daylight saving. ")
please see this piece of code to grok the complicated ways of java time:
#Test
public void testDST() {
final TimeZone met = TimeZone.getTimeZone("MET");
Calendar gc = new GregorianCalendar(met);
final long timeInMillis = gc.getTimeInMillis();
final long gmtTime= timeInMillis-(gc.getTimeZone().getOffset(timeInMillis));
final Date gmtDate = new Date(gmtTime);
System.out.printf("%-40s: %tc\n%-40s: %tc\n%-40s: %tc\n%-40s: %d\n%-40s: %d",
"new Date() (local timezone)",new Date(),
"UTC", gmtDate ,
"now from Calendar with TC GMT+02:00",gc,
"zoneoffset",gc.get(Calendar.ZONE_OFFSET),
"dst savings",met.getDSTSavings());
}
You can also define your own SimpleTimeZone and provide custom DST rules, however, i have not found out how to get this information from the predefined TimeZones.
You should also be aware, that if TimeZone.getTimeZone(TZName) does not find the specified timezone, it does not throw an exception, but it just uses GMT, which can cause major misunderstandings.
You can find all this information (and a lot more) in javadoc for Calendar, TimeZone, Date, etc.
There are few methods available in java.util.TimeZone to get Daylight Saving Time. Please check out the BlackBerry Java Docs page.