Recall the hamburger analogy.  If the OP has eaten McDonalds before my gourmet burger is ready then they won't be hungry when it arrives.

That's not how long the SQL code takes to execute.  Tally based method would crush the OP's kludge especially as their test case is  spanning thousands of days.

19 minutes is...

Yes, sorry.  This is the preferred answer. ...

Here's another one.  It took 19 minutes vs 12 minutes for the rCTE.  There's no sample data and no time for making any up.  Hopefully the query is...

Here's another one.  It took 19 minutes vs 12 minutes for the rCTE.  There's no sample data and no time for making any up.  Hopefully the query is sound.  It...

Any time I've needed to populate a table of sequential numbers, I just done it by brute force. No recursion or fancy stuff. Remember the definition of place valued...

Here's a set of comparisons between fnNumbers and fnTally

Performance comparison of fnNumbers vs fnTally inserting 10x row counts (n=1,000)

Performance comparison of fnNumbers vs fnTally inserting 10x row counts...

Here are new Fiddles.  The old Fiddles were not in this more popular Fiddle.  There's more than one Fiddle FYI.

Performance comparison of fnNumbers vs fnNumbersRC inserting 10x row counts...

If you look at my answer count v.s. the number of points I have and the position I have on Stack Overflow, you'll see that quantity doesn't matter much...

Steve, You've got a wrong analogy here.

The better one would be this:;

You live in late Soviet Union and have to choose which car to buy: Porsche 911 and ZAZ...

The WHILE loopers always think everyone else is/are crazy.  That person's query also...

Ah... almost forgot... What to do about the folks that claim that performance doesn't matter if you know that here will always only be a small number of rows...

Ok here are two recent winning recursive cte's.  Be gentle when evaluating the opposing answers 🙂

https://stackoverflow.com/questions/63922869/get-an-interval-of-dates-from-a-range-of-dates/63923536

https://stackoverflow.com/questions/63919706/fill-missing-months-on-a-date-query/63920844

As a bonus, here losing while using an ordinal splitter

https://stackoverflow.com/questions/63886788/extracting-date-from-text-in-sql-using-cursor/63887736

Here's a DB Fiddle that shows fnNumbers is about 4-10x faster to generate 100,000 rows.

Here's a DB Fiddle that shows fnNumbers is about 2x faster to generate 10,000 rows.

Here's...

It should be said I'm not looking for an advantage not available to anyone else.  As soon as a different method works the others will just switch and then it's...