Views calendar pager is skipping months [#2823890]

Problem/Motivation

After creating a monthly calendar in Views, using the pager results in months being skipped over.

Steps to repeat

Add Views Templates module
Add Calendar module
Create content type and add date field
In Views, create a view from a template using the previously added date field
Using the pager on this calendar results in months being skipped over

Expected Results

Site visitor should be able to navigate backwards and forwards through all months without months being skipped over.

Actual Results

Months are skipped over when using the pager and site visitors are unable to use the previous button.

Comments

Comment #1

31 October 2016 at 21:08

design_ev created an issue. See original summary.

Comment #2

mpdonadio

he/him

English

Philadelphia/PA/USA (UTC-5)

CreditAttribution: mpdonadio at DiD Agency commented 31 October 2016 at 21:44

Project:	Drupal core	» Calendar
Version:	8.2.x-dev	» 8.x-1.x-dev
Component:	datetime.module	» Code

I think this should start in the Calendar module, which is providing the pager in this case?

Comment #3

Andreas Radloff CreditAttribution: Andreas Radloff commented 2 November 2016 at 10:36

THis happends to me when on the 31st of the month. The pages seems to add or subtract 30 days instead of one month so when on October 31 you cannot go to november because the pager points 30 days ahead to Dec 1 and when on July 31 the previous pager points to July 1st. Here's where it happends in class CalendarPager:

  protected function getPagerArgValue($mode) {
    $datetime = $this->argument->createDateTime();
    $datetime->modify($mode . '1 ' . $this->argument->getGranularity());
    return $datetime->format($this->argument->getArgFormat());
  }

Seems to be well known bug judging by the comments here: http://php.net/manual/en/datetime.modify.php