PHPSpreadsheet: Formatting a cell for time also includes the date - php

Question

I am trying to format a time cell using PHPSpreadsheet but it seems to be including the date as well when looking at the formula bar. There also seems to be some inconsistency when converting from a string, datetime object or unix timestamp.
<?php
include '../vendor/autoload.php';
use \PhpOffice\PhpSpreadsheet\Spreadsheet;
use \PhpOffice\PhpSpreadsheet\Writer\Xlsx;
$times = [
'16:00:00',
new \DateTime('16:00:00'),
\strtotime('16:00:00'),
'2020-04-04 16:00:00',
new \DateTime('2020-02-04 16:00:00'),
\strtotime('2020-02-04 16:00:00'),
];
$format = \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME1;
$spreadsheet = new Spreadsheet();
$sheet = $spreadsheet->getActiveSheet();
foreach ($times as $i => $time) {
$sheet->setCellValue('A' . ($i+1), \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($time));
$sheet->getStyle('A' . ($i+1))->getNumberFormat()->setFormatCode($format);
}
$writer = new Xlsx($spreadsheet);
$writer->save('test.xlsx');
From \PHPOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME1: const FORMAT_DATE_TIME1 = 'h:mm AM/PM';
Is this a bug or intended functionality? Considering as const FORMAT_DATE_DATETIME = 'd/m/yy h:mm'; does include some date parameters I think there's something wrong happening.
Here's some screenshots of what happens:
But if we type in "5:00 AM" into a cell, the formula bar does not include the date:
Here is the screen that pops up from Right Click > "Format Cell":
Can someone please tell me if I'm doing something wrong, thankyou.

Answer 1

I figured out how to fix this problem: You need to calculate the Excel representation of the timestamp and then get only the numbers after the decimal place.
<?php
$timestamp = new \DateTime('16:00:00');
$excelTimestamp = \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($timestamp);
$excelDate = floor($excelTimestamp);
$time = $excelTimestamp - $excelDate;
From the documentation:
In Excel, dates and Times are stored as numeric values counting the number of days elapsed since 1900-01-01. For example, the date '2008-12-31' is represented as 39813. You can verify this in Microsoft Office Excel by entering that date in a cell and afterwards changing the number format to 'General' so the true numeric value is revealed. Likewise, '3:15 AM' is represented as 0.135417.
I hope this helps anybody else stuck with this problem.

Answer 2

You must set the right number format see for more information the official sample documentation.
The number format that you set is 'h:mm AM/PM' means that there is no date included only the time.
When you change to 5 PM you overwrite the content and the number format will used.
If you will have a date you should try to set 'd/m/yy h:mm AM/PM'.