Subtracting data in <day> <hour>:<minute>:<second>

Dear Kristy_Zim 

It is a little tricky to understand what you are after exactly.

However, if I assume that:

• The month and year of the data is not relevant (it can be any month or year)
• You wish to subtract "Customer placed order datetime" FROM "Placed order with restaurant datetime", so that you can achieve the goal:
• "Determine how long after the customer placed the order the order was placed with the restaurant", while
• Display the result in the same format as the input data (dd HH:mm:ss)

Then you can use something like this:

=TEXT(VALUE("2022-01-"&B2)-VALUE("2022-01-"&A2),"dd HH:mm:ss")