SQL Query

What you have is fine.  Is this a one time thing?  If dates are being updated with 1900-01-01 00:00:00.000 as an insert, the more efficient thing to do from the start is insert a NULL value if there is no date.  

<%
newDate="NULL"
If request("date")<>"" then
   if isdate(request("date") then
        newDate=request("date")
   end if
end if

sql="insert ..... datefield='"&newDate&"'"

%>

I think you will find that even if you set those values to NULL, T-SQL will return '1900-01-01 00:00:00.000' as a default value.  In all the postings I've seen, you can't get it to return NULL, just the default date of '1900-01-01 00:00:00.000'.

Dave, I know at least in ms sql I set dates to NULL if  they are not available at time of creating the record (such as a birthdate) and they remain null.  However, when displaying the record for editing or searching, I set the sql to something like

ISNULL(CAST(BirthDate AS varchar(20)), '')  or ISNULL(CAST(BirthDate AS varchar(20)), 'No Date Avail')

It's a two part question.  If you set it to NULL on INSERT, what does a basic SELECT return?  And if it is actually NULL as opposed to a default value, how do you detect that?

This is not a one time thing. I load the schedules from Excel to SQL Server, and at that point all days off show as NULL. But whenever users updated the records the NULLs change to '1900-01-01 00:00:00.000'. When I'm paging the records I use the following HTML to display e.g. the Tuesday column:

<%If IsNull(rs("TueIn")) or rs("TueIn")="" Then %>
<td align="center" colspan="2" bgcolor="#ffffff">
<font color="#cc0000" style="font-size:80%">TUE</font></td><%else%>
<td align="center"><small><small><%=FormatDateTime(rs("TueIn"),vbshorttime)%></small></small></td>
<td align="center"><small><small><%=FormatDateTime(rs("TueOut"),vbshorttime)%></small></small></td><%end if%>

When the TueIn record is NULL the letters 'TUE' are displayed but after a record is updated the NULL in the database becomes '1900-01-01 00:00:00.000' and instead of 'TUE' the record shows 00:00 for both TueIn and TueOut. That's why I added the Update SQL attached. Whenever the user updates a record the same submission resets the values to NULLs. I was just wondering if there is a better way to do it. Maybe by doing something with the if statement in the HTML. I tried ***or rs("TueIn")="1900-01-01 00:00:00.000"*** but it didn't work. Your previous answer was useful, I just didn't know how to insert it in my HTML to also display the Out time in the same column.

Thank you so much!

On another note for efficiency,  why do you have different fields for each day of the week?  Couldn't you just use one date, then use vb or sql to extract or search based on the weekday?    Check out the weekday and weekdayname functions  http://www.w3schools.com/vbscript/vbscript_ref_functions.asp#date