TYPO3 Core

The Backend should show the default-date `01-01-1970 00:00`. Some Definition show the Time `01-01-1970 00:*32*`
Some of the Default-Definition in the TCA of the column won't work.

            'config' => [
                'type' => 'input',
                'size' => 30,
                'eval'     => 'datetime',
                'dbType'   => 'datetime',
                'default'  => 0,    // okay 
//                'default'  => '1970-01-01 00:00:00', // wrtong shows in backend  01-01-1970 00:32
//                'default'  => SelfConst::DEFAULT_START_STOP_TSTAMP, // okay  (= 0)
//                'default'  => SelfConst::DEFAULT_START_STOP_VERSION, // wrong shows in backend  01-01-1970 00:32 (= '1970-01-01 00:00:00')
//                'default'  =>  mktime(0,0,0,1,1,1970), // shows in Backend 01-01-1970 00:00
//                'default'  => ( new \Datetime(
//                    SelfConst::DEFAULT_START_STOP_VERSION,
//                    new \DateTimeZone(SelfConst::DEFAULT_START_STOP_TIMEZONE))
//                )->getTimestamp(),  // okay 01-01-1970 00:00
//                'default'  => new \DateTime(SelfConst::DEFAULT_START_STOP_VERSION, new DateTimeZone(SelfConst::DEFAULT_START_STOP_TIMEZONE)), // disaster
//                          crash with error-message in IRRE-Element (Error 500 - Internal Server Error)
                //(1/1) #1476107295 TYPO3\CMS\Core\Error\Exception
                // PHP Catchable Fatal Error: Object of class DateTime could not be converted to string in /var/www/html/Source/web/typo3/sysext/backend/Classes/Form/FormDataProvider/DatabaseRowDefaultValues.php line 61

                'readOnly' => true,
            ],

P.S. The Screenshot in BUG #88450 shows the Default-Time '01.01.1970 01:33`.