In MySQL, NOW() will return the date in yyyy-mm-dd h:m:s format:
2009-10-30 10:25:24
you can remove the seconds using the DATE_FORMAT() function:
DATE_FORMAT(NOW(), '%Y-%m-%d %h:%m')
So in your SQL you can use:
tasksTable.TaskDateTime = DATE_FORMAT(NOW(), '%Y-%m-%d %h:%m');