DECLARE @now datetime

SET @now = GETDATE()

select convert(nvarchar(MAX), @now, 0) as output, 0 as style

union select convert(nvarchar(MAX), @now, 1), 1

union select convert(nvarchar(MAX), @now, 2), 2

union select convert(nvarchar(MAX), @now, 3), 3

union select convert(nvarchar(MAX), @now, 4), 4

union select convert(nvarchar(MAX), @now, 5), 5

union select convert(nvarchar(MAX), @now, 6), 6

union select convert(nvarchar(MAX), @now, 7), 7

union select convert(nvarchar(MAX), @now, 8), 8

union select convert(nvarchar(MAX), @now, 9), 9

union select convert(nvarchar(MAX), @now, 10), 10

union select convert(nvarchar(MAX), @now, 11), 11

union select convert(nvarchar(MAX), @now, 12), 12

union select convert(nvarchar(MAX), @now, 13), 13

union select convert(nvarchar(MAX), @now, 14), 14

--15 to 19 not valid

union select convert(nvarchar(MAX), @now, 20), 20

union select convert(nvarchar(MAX), @now, 21), 21

union select convert(nvarchar(MAX), @now, 22), 22

union select convert(nvarchar(MAX), @now, 23), 23

union select convert(nvarchar(MAX), @now, 24), 24

union select convert(nvarchar(MAX), @now, 25), 25

--26 to 99 not valid

union select convert(nvarchar(MAX), @now, 100), 100

union select convert(nvarchar(MAX), @now, 101), 101

union select convert(nvarchar(MAX), @now, 102), 102

union select convert(nvarchar(MAX), @now, 103), 103

union select convert(nvarchar(MAX), @now, 104), 104

union select convert(nvarchar(MAX), @now, 105), 105

union select convert(nvarchar(MAX), @now, 106), 106

union select convert(nvarchar(MAX), @now, 107), 107

union select convert(nvarchar(MAX), @now, 108), 108

union select convert(nvarchar(MAX), @now, 109), 109

union select convert(nvarchar(MAX), @now, 110), 110

union select convert(nvarchar(MAX), @now, 111), 111

union select convert(nvarchar(MAX), @now, 112), 112

union select convert(nvarchar(MAX), @now, 113), 113

union select convert(nvarchar(MAX), @now, 114), 114

union select convert(nvarchar(MAX), @now, 120), 120

union select convert(nvarchar(MAX), @now, 121), 121

--122 to 125 not valid

union select convert(nvarchar(MAX), @now, 126), 126

union select convert(nvarchar(MAX), @now, 127), 127

--128, 129 not valid

union select convert(nvarchar(MAX), @now, 130), 130

union select convert(nvarchar(MAX), @now, 131), 131

--132 not valid

order BY style

Here's the result

output                   style

Apr 28 2014  9:31AM          0

04/28/14                     1

14.04.28                     2

28/04/14                     3

28.04.14                     4

28-04-14                     5

28 Apr 14                    6

Apr 28, 14                   7

09:31:28                     8

Apr 28 2014  9:31:28:580AM   9

04-28-14                     10

14/04/28                     11

140428                       12

28 Apr 2014 09:31:28:580     13

09:31:28:580                 14

2014-04-28 09:31:28          20

2014-04-28 09:31:28.580      21

04/28/14  9:31:28 AM         22

2014-04-28                   23

09:31:28                     24

2014-04-28 09:31:28.580      25

Apr 28 2014  9:31AM          100

04/28/2014                   101

2014.04.28                   102

28/04/2014                   103

28.04.2014                   104

28-04-2014                   105

28 Apr 2014                  106

Apr 28, 2014                 107

09:31:28                     108

Apr 28 2014  9:31:28:580AM   109

04-28-2014                   110

2014/04/28                   111

20140428                     112

28 Apr 2014 09:31:28:580     113

09:31:28:580                 114

2014-04-28 09:31:28          120

2014-04-28 09:31:28.580      121

2014-04-28T09:31:28.580      126

2014-04-28T09:31:28.580      127

28 جمادى الثانية 1435  9:31:28:580AM    130

28/06/1435  9:31:28:580AM    131

Make nvarchar(max) shorter to trim the time. For example:

select convert(nvarchar(11), GETDATE(), 0)

union select convert(nvarchar(max), GETDATE(), 0)

outputs:

May 18 2018

May 18 2018  9:57AM