Good news - the problem will be solved itself on Monday Jan, 4.
It assumes these first days as a week number 53. That's why we have year 2017.
A added some lines of code to work around the problem.
As jedivader said you should modify file
administrator\components\com_booking\helpers\booking.php
in function:
function getWeekCalendar(&$subject, &$setting, $count = 'week', $isAdmin = false, $rids = null)
make some changes:
1. Instead of
$setting->current = $current->format('Y-W');
put
if ((int) $current->format('W') > 52) {
$setting->current = $current->format('Y') . '-01';
} else {
$setting->current = $current->format('Y-W');
}
2. AFTER (not instead)
$setting->week = $setting->defaultWeek? $setting->defaultWeek : 1;
add
if ($setting->week > 52) $setting->week = 1;
On my testing environment it works.
