Sql-server – What data is causing an NVARCHAR/DATETIME conversion error

I checked your profile and saw that you are in the UK. If your sql server is set to use the dateformat dmy then that explains your issue. Without using the 'T' instead of the space in the datetime string, Sql Server won't recognize it as ISO8601 format.

Try this:

select count(*) 
  from dbo.profile 
  where [created] between convert(datetime,'2014-11-01T00:00:00.000') 
                      and convert(datetime,'2014-11-30T23:59:59.997');

Querying using dates and/or datetimes can be tricky, to make sure you are getting what you are looking for I recommend reading:

• Aaron Bertrand's Bad habits to kick : mis-handling date / range queries
• Robyn Page's SQL Server DATE/TIME Workbench

edit: to clarify the out of range value in your error message would be from interpreting the month as 30 and the day as 11.

Since you are not shared the sample data of the Gradd19 value, I suspect the date value is in the yyyy-dd-mm format, so when trying to convert (month value more than 12) it cause the out-of-range value error.

For sample, if the date format in yyyy-mm-dd, it will execute properly:

DECLARE @FromDate DATETIME;
DECLARE @Gradd19 AS VARCHAR (20) = '2016-11-15';
SELECT @FromDate = CONVERT(VARCHAR, @Gradd19, 105);
SELECT @FromDate;

Incase if it is in yyyy-dd-mm it will throw out-of-range value error

DECLARE @FromDate1 DATETIME;
DECLARE @Gradd191 AS VARCHAR (20) = '2016-15-11';
SELECT @FromDate1 = CONVERT(VARCHAR, @Gradd191, 105); 
SELECT @FromDate1;

So in that case you need do one more conversion to skip the issue, like the below:

DECLARE @FromDate2 DATETIME;
DECLARE @Gradd192 AS VARCHAR (20) = '2016-15-11';
SELECT @FromDate2 = CONVERT(VARCHAR(19), CONVERT(DATETIME, @Gradd192, 105), 120)
SELECT @FromDate2;

So instead of

CONVERT(VARCHAR, Gradd19, 105) AS ExpiryDate

you need to use

CONVERT(VARCHAR(19), CONVERT(DATETIME, Gradd19, 105), 120) AS ExpiryDate

Update: As you mentioned in the comments the Gradd19 having the values of 20 and 60, it is difficult to filter those non-valid data. But based on the LEN() function you may avoid the non-valid data, then using the CONVERT you can get the VARCAHR field as DATETIME value.

Based on your sample data the valid date's minimum length is 10 characters, so you can apply the condition in the WHERE clause.

Sample execution:

DECLARE @GradedDETAILS  TABLE (Gradd19 VARCHAR (30));

INSERT INTO @GradedDETAILS (Gradd19) VALUES
('Sep 16 2016 12:00AM'),
('Sep 16 2016 12:00AM'),
('Sep 16 2016 12:00AM'), 
('Sep 19 2016 12:00AM'), 
('Sep 19 2016 12:00AM'), 
('Sep 16 2016 12:00AM'), 
('20'), 
('60'), 
('20-09-2016'), 
('20-09-2016');

SELECT CONVERT(VARCHAR(19), CONVERT(DATETIME, Gradd19, 105), 120)
FROM @GradedDETAILS
WHERE LEN(Gradd19) >= 10

So in your actual query also you need to add the LEN(Gradd19) >= 10 condition and in the SELECT use this to convert as DATETIME by CONVERT(VARCHAR(19), CONVERT(DATETIME, Gradd19, 105), 120)