Сделайте это с echo date('Y:W:j:H:i');
PHP Manual date
Y A full numeric representation of a year, 4 digits Examples: 1999 or 2003
W ISO-8601 week number of year, weeks starting on Monday Example: 42 (the 42nd week in the year)
m Numeric representation of a month, with leading zeros 01 through 12
j Day of the month without leading zeros 1 to 31
H 24-hour format of an hour with leading zeros 00 through 23
i Minutes with leading zeros 00 to 59
По вашей проблеме обратитесь к Как создать дату / время из номера недели Здесь Демо
$str = '2019-45-09 12:07';
$arr = explode(" ",$str);
$date_arr = explode("-",$arr[0]);
$time_arr = explode(":",$arr[1]);
$date = new DateTime();
$date->setISODate($date_arr[0],$date_arr[1],$date_arr[2])->setTime($time_arr[0],$time_arr[1]);
echo $date->format("Y-W-d H:i:s") . PHP_EOL;
$date->add(new DateInterval("P1D"));
echo $date->format("Y-W-d H:i:s");