Shell Programming and Scripting

I have read many threads, but I still didn't find the right answer. May be i didn't find the right thread, though are so many threads for the same question.

Basically the situation is - find date in a file and replace it with another date. (its not homework, its part of lot of a big processing, so just extracting this piece of problem)
A file would contain records like this
john 2011/06/28 11:16:14
smith 2011/06/28 12:46:10
jessica 2011/06/28 06:16:40

I need to find john, replace the date on the same line with another date. I can find the required line, i am facing problem replacing the date. Here is the extracted code.

record="john 2011/06/28 11:16:14"
oldDate="2011/06/28 11:16:14"
newDate="2011/06/28 45:56:67"
echo $record | sed 's|'$oldDate'|'$newDate'|g'

Hence i get
sed: -e expression #1, char 21: unterminated `s' command

I got to know it has to do with the characters "\" & ":", but what exactly is the problem and what is the solution?
Can anybody explain me please?

---------- Post updated at 12:54 PM ---------- Previous update was at 12:48 PM ----------

Just figured out that I could replace the date and time separately, but not together. I think the space between the date and time is the problem.
Am I right?

Try:

Code:

echo $record | sed 's|'"$oldDate"'|'"$newDate"'|'

I believe it's a shell's problem.

I have tried almost all sorts of combinations, none of them have worked. Even this one didn't work.
I want to understand what's happening behind the scene.

The below would not throw sed error posted by you.. but it neither matches the oldDate. Storing the pattern in a variable and trying to match it in Sed is IMO a bad idea. However you can try as

Code:

echo 'john 2011/06/28 11:16:14' | sed "s|$oldDate|$newDate|"

Thanks yazu and michael for your inputs.
But it didn't work.

michael, as per your suggestion, if i dont have stored a pattern in a variable, then how to I search?
I will explain my problem
1. I get a name as input to the shell script.
2. Search for the name in a file (I have mentioned how the file look like in my first post)
3. Replace the old date with the new date

What was I trying to do it?
1. Have the new date and old date in variables
2. Replace the old string with the new string in the file

Now I have changed step 2 to
2. Delete the line which has the name
3. Insert a new line along with name and new date.

Ok before that.. Does the above Sed produced any desired output of yours..?

I output is same as input "john 2011/06/28 11:16:14"