It took 5 months. Our DS-260 got approved on December 2021 and we were notified about the interview appointment scheduling in April 2022. It may have taken this long, though, due to backlogs from the pandemic.
One very big piece of advice - do not make assumptions around when you will receive your visa. We re-scheduled my spouse's medical appointment/visa interview date to early October 2022 (due to some previous plans we already had for the summer) and thought it would all be wrapped up by November 2022. It's now the end of January 2023 and things are not resolved. We were unexpectedly delayed multiple times due to:
1. Medical exam - when my spouse went for the medical exam, it was a requirement for *all* applicants to get a sputum test for tuberculosis (which added 10 weeks to the timeline as that's how long it takes for the cultures to grow). If you have some sort of pre-existing medical condition, you would also be wise to come with a note from your doctor stating that it is under control and does not pose any challenges (otherwise, you will be asked to return with this in hand)
2. When my spouse went to the visa interview in December 2022, we were asked to upload the latest copy of our tax returns to CEAC since what was approved in the DS-260 pertained to the 2020 tax year and we were at the end of 2022 ( to our credit, we brought in the physical copy of our 2021 tax returns but they wanted this uploaded to CEAC as well and we did not know about this beforehand) and also to provide the *original* copy of the NBI clearance (since we brought a copy by accident). We were issued a 221G letter for this
3. One month later after mailing in the documents above, we found out (through another 221G) that we needed to complete Form DS-5535 (who knows why - maybe because we traveled internationally after the DS-260 got approved and they needed to conduct a background check on this). The wait time for DS-5535 to clear is very long based on what I've heard and I'd be delighted to hear it being wrapped up by end of this year (and will be absolutely floored if it's sooner than that)
Point being - do not make plans in advance of time. This process is rife with delays that you cannot foresee no matter how much research you do online or how many immigration lawyers you consult. Come well-prepared to the interview with *original* copies of all documents. If your NBI clearance is about to expire, get a new one and pre-upload it to CEAC. Make note of whether they would logically ask you for physical copies of your latest tax returns (like in my case above) and pre-upload these documents to CEAC in advance of the interview. Bring a pre-filled out Form DS5535 in case they ask you for it. This is a waiting game and closing every potential opportunity for delay can only help you.