Update Date.php

[Scorpshn]

isset and !isset is not working because the $tmp date values are set to false. Replace with !empty and empty
Ex
if (!empty($tmp_start_date)) = false
because
($tmp_start_date = $this->_is_format_valid($this->attributes['direction'][0]))
function _is_format_valid return false and set $tmp_start_date
!empty and empty test for isset and if the value is false or ''

Add test for if date $obj->direction(array(1, 7)); to add the first array value to the second otherwise it will give error on the 7th day
Ex. if today is 2017-07-17
2017-07-18
2017-07-25 gives error because test till 2017-07-24

add the if in line 1147
if $obj->direction(array(5,7)); check for 7 days not working because $this->attributes['direction'][0] not added to $this->attributes['direction'][1] from today

add the if in line 1150
if $obj->direction(array('2017-07-18', 7')); to check 7 days didn't work because system_date used and not $this->attributes['direction'][0])

added the same to get the start date if you have the end date line 1189