Msg 242: conversion of a varchar data type to a datetime data type resulted in an out-of-range value

I have gone through a bunch of posts here with this error and tried changing data types and used Convert but nothing seems to fix this. So I would like to ask for some help here. I will try to give as much info, but feel free to ask if its not enough.

This is where I am getting the error:

Insert into prompt(ID, Date)  
    select 
        ROW_NUMBER() over (order by b.IDLoc),
        [dbo].[fn_GetGPtime](cast (replace(DateCollected, '/', '-') + ' ' + a.UTCTime as datetime))
    from 
        Img a 
    inner join 
        Tloc b on a.Filename = b.filename
    order by 
        b.IDLoc 

The Date column in prompt table has a datatype of float. UTCTime and DateCollected are both varchar(20)

The error is:

Msg 242, Level 16, State 3, Line 274
The conversion of a varchar data type to a datetime data type resulted in an out-of-range value.

Here is the function:

[dbo].[fn_GetGPtime] (@UTCtime datetime)
returns varchar(50)
AS
BEGIN
    return (DATEPART (WEEKDAY, @UTCtime) - 1) * 86400 ---day
            + DATEPART (HOUR, @UTCtime) * 3600 ---hour
            + DATEPART (MINUTE, @UTCtime) * 60 ----minutes
            + DATEPART (SECOND, @UTCtime) ---second
            + (DATEPART (MILLISECOND, @UTCtime)) * 0.001 ---ms
            + (DATEPART (MICROSECOND, @UTCtime)) * 0.000001 ---us
            + 16 ----leap seconds
end;

To get an idea of the data itself:

How do I fix this issue?

Answer

Your error message could mean two different things: that you have non-convertible data in some cells, or that field’s data are not convertible to datetime at all.

You can use try_convert instead of convert to figure out which it is. It will solve your problem if you have a few completely unusable values (i.e. bad data); you’ll get nulls for bad data and good conversion for good data. If the overall conversion is never going to work you’ll get all nulls and you’ll know it isn’t just a few bad values.

Another thing you could try is converting from float to numeric before converting to datetime. I find that float formatted data are awful for conversions and converting to numeric can remove many issues. You’d have something like convert(datetime, convert(numeric(18,2), UTCTime))