Will January 23 SAT IIs be in time for regular decision?

Will colleges accept the January 23 SAT date for regular decision? Will they wait for my score before reviewing my application?

Depends on the school. You need to check their web-site for the test deadlines. If they say that they accept scores that late, then presumably, they will wait for the score if they know it’s coming - but you’ll need to ask. Many schools have December testing deadlines for this reason.

Most likely YES. But like N’s Mom said, each school’s testing deadlines should be prominently displayed

You need to check each colleges rules. A large number of colleges require all testing to be completed by December. An equally large number accept through the Jan test, and some even the Feb ACT. However, for many of those who accept the Jan test you need to identify the college in your test registration as one to automatially be sent scores upon release, such as including them in your four free sends, to assure the test scores arrive in time to be considered. That results in the fastest form of delivery, but you will not know your scores before they are sent.