Pulling my hair out again...
I need to calculate the difference between two dates in days. I'm doing this:
<cfset d = DateDiff("d", Dateformat( active_apps.app_base_coupon_start, "dd.mm.yyyy"), Dateformat( variables.useDate, "dd.mm.yyyy") )>
With active_apps.app_base_coupon_start = 27.07.2012 and variables.useDate = today = 02.10.2012.
I dumped both values, they are OK. However the dateDiff returns -168 when I was looking for (4 days in July, 31 in August, 30 in September, 2 in October) 67 days.
Question:
Can someone prevent me from losing my remaining hair and tell me what I'm doing wrong here or if there is an easier way to get the difference in days?
EDIT:
Ok, it also works like this:
<cfif DateAdd("d", active_apps.app_grace_time, Dateformat( active_apps.app_base_coupon_start, "dd.mm.yyyy") ) GT now()>
<cfdump output="e:\s\page\t\dump.txt" label="catch" var="YUP">
<cfelse>
<cfdump output="e:\s\page\t\dump.txt" label="catch" var="NOPE">
</cfif>
but I would still like to know, why dateDiff is returning strange values.
DateDiff("datepart", date1, date2) takes a datepart and two date objects as arguments.
DateFormat() as Adam Cameron already said returns a string and not a date object.
ColdFusion is trying to read "27.07.2012" and "02.10.2012" as date objects by trying to apply some known date formats. That's why "02.10.2012" is interpreted as "Feb 10 2012".
I wouldn't let ColdFusion guess the dateformat of your string. Instead you should create date objects by using CreateDate(year, month, day).
now() is also a ColdFusion date object.
First things first, dateAdd() takes DATES as arguments, not dateFormat()-ed strings. dateFormat() is for output, not for calculations.
You need to understand that just because "02.10.2012" looks like a date to you (and to me), it's not a date as far as the computer is concerned: it's a string.
Never use strings for date calculations.
In your case, CF is valiantly trying to work out what "02.10.2012" might mean as a date, and deciding it's "mm.dd.yyyy" format, which is Feb 10, whereas you mean Oct 2.
You're using an ambiguous date format. Change the DateFormat to international date format (ISO 8601) whenever you make date calculations and things will be a bit more predictable. Note that CF doesn't support every variant of the ISO format, but for the most part you just need yyyy-mm-dd which is supported.
<cfset d = DateDiff("d", Dateformat( active_apps.app_base_coupon_start, "yyyy-mm-dd"), Dateformat( variables.useDate, "yyyy-mm-dd") )>
Related
With today's date, I should get the 16th date of next month.
For example, on passing 13-12-2021, I should get 16-01-2022.
I need to get the next month 16th day from current date (input date). Examples:
On passing 13-11-2021 should get 16-12-2021.
On passing 14-11-2021 should get 16-12-2021.
On passing 15-11-2021 should get 16-12-2021.
On passing 02-12-2021 should get 16-01-2022.
On passing 03-12-2021 should get 16-01-2022.
On passing 03-01-2022 should get 16-02-2022.
On passing 04-01-2022 should get 16-02-2022.
Any help will be much appreciated. Thanks.
java.time
One of the many strong points of java.time, the modern Java date and time API, is date arithmetic like this.
public static LocalDate nthDayOfFollowingMonth(
int desiredDayOfMonth, LocalDate currentDate) {
return YearMonth.from(currentDate)
.plusMonths(1)
.atDay(desiredDayOfMonth);
}
Try it out with your example date:
System.out.println(nthDayOfFollowingMonth(
16, LocalDate.of(2021, Month.DECEMBER, 13)));
Output:
2022-01-16
We might not have needed to convert to YearMonth and back to LocalDate. Doing so relieves both me and the reader of considering what happens if today’s day of month doesn’t exist in next month — for example if current date is 30 January (there is no 30 February). What one still wants to consider is what happens if you request a day of month tht doesn’t exist next month. For example on 13 January asking for the 30th of next month. We can try that out too:
System.out.println(nthDayOfFollowingMonth(
30, LocalDate.of(2022, Month.JANUARY, 13)));
I find the result very reasonable:
java.time.DateTimeException: Invalid date 'FEBRUARY 30'
I am trying to get a date from its integer components: I have day, month and year as variables (that can change, I don't want to hard code them), and I want to reunite them in a date variable.
For example, something like that;
myDay: 15
myMonth: 4
myYear: 2016
`date$(myYear,myMonth,myDay) --> should return 2016.4.15 (formatted as a date).
Any way to do that?
Thank you
q)d:3
q)m:8
q)y:2016
q)"D"$"." sv string (y;m;d)
2016.08.03
See cast vs tok - need to use different arguments depending on if what you're casting from is a string or not
I have a ISO8601 string (e.g. date="2015-07-10T04:31:25") I need to convert this to the format:
July 7, 2015, 4:31:25 PM (EDT)
Even though I can write a template and use substring() to transform the string in the date time format. However I am not sure how to achieve the AM/PM and time zone information?
Working code templates would be highly appreciated. Thanks!
I am not sure how to achieve the AM/PM ...
It can be calculated from the hour component as:
substring('AMPM', 1 + 2*(number($hour) > 11), 2)
Of course, in the given input, where $hour would be "04", the correct result is "AM", not "PM".
... and time zone information?
Your input does not contain any time zone information, so unless you want to hard-code EDT as a string, there is no way to get it.
I am new to Noda Time and I basically want to compare if a date has expired or not. In my case I have an object with the date it was created, represented by a LocalDate and the amount of months it's valid as an int, so I wanted to do a simple:
if ( Now > (dateCreated + validMonths) ) expired = true;
But I can't find in the Noda Time documentation the proper way to get the Now Date (they only show how to get the Now Time as SystemClock.Instance.Now) and the proper way to handle time comparisons.
For example if today is January 1st 2015 and the document was created in December 1st 2014, and it was valid for one month, today it expires its one month validity.
I miss methods such as isBefore() and isAfter() to compare dates and times. Simple overloads of the < > operators could also be very helpful.
EDIT:
1 - Sorry, there are < > operators to compare dates.
2 - I solve my problem using this code (not tested yet!):
...
LocalDate dateNow = this.clock.Now.InZone(DateTimeZoneProviders.Tzdb.GetSystemDefault()).LocalDateTime.Date;
LocalDate dateExpiration = DataASO.PlusMonths(validity);
return (dateNow < dateExpiration);
To get the current date, you need to specify which time zone you're in. So given a clock and a time zone, you'd use:
LocalDate today = clock.Now.InZone(zone).Date;
While you can use SystemClock.Instance, it's generally better to inject an IClock into your code, so you can test it easily.
Note that in Noda Time 2.0 this will be simpler, using ZonedClock, where it will just be:
LocalDate today = zonedClock.GetCurrentDate();
... but of course you'll need to create a ZonedClock by combining an IClock and a DateTimeZone. The fundamentals are still the same, it's just a bit more convenient if you're using the same zone in multiple places. For example:
// These are IClock extension methods...
ZonedClock zonedClock = SystemClock.Instance.InTzdbSystemDefaultZone();
// Or...
ZonedClock zonedClock = SystemClock.Instance.InZone(specificZone);
With DateJS, you'd add e.g. six months to the current date like this:
Date.today().addMonths(6);
However, I need to add 24 months not to today's date, but to a date which a user has typed into a date field. So the today() should in principle be replaced by something like this.getField('begin_date').value.
The result shall be written into another data form field.
I tried hard, but couldn't make it. Can anyone help me out?
Providing the input value is a textual representation of a date, you need to convert it into a Date object at the first place. Then you can work with it as you want.
DateJS has a pretty smart parse() function which does exactly that, so you'd achieve it like this:
Date.parse(this.getField('begin_date').value).addMonths(24)
When a specific date format is needed, like DD.MM.YYYY commonly used in Europe, you can use parseExact() and specify the format. Like this:
Date.parseExact(dateToParse, 'dd.MM.yyyy') // leading zeroes required; parses 01.04.2014 but not 1.4.2014
Date.parseExact(dateToParse, 'd.M.yyyy') // leading zeroes not required; parses both 01.04.2014 and 1.4.2014
Here is a solution that I found for my problem, using DateJS as well:
start = this.getField('begin_date').value;
var d1 = util.scand("dd.mm.yyyy", start);
var myDate = new Date(d1);
result = myDate.addMonths(24);
This works pretty fine, also spanning leap years, except for the 28th of February, 2014/2018/2022 ... ; the result then will be the 28th of February, 2016/2020/2024 ... and not the 29th of February 2016/2020/2024... In these cases it's up to the user to accept the 28th or to manually change the date to the 29th.