We applied earlier this fall and it took about 2 weeks after the application review date for the month to hear back about whether or not DD was invited out for an assessment day.
One piece of advice I would give you is to be sure to look for the email stating that your application is complete before the due date. We hadn't gotten one and when we checked with Davidson about it we found out that they didn't have everything. It was quickly cleared up and the entire application was found in time for the review, but if we hadn't called to check, we wouldn't have been reviewed the month we had hoped to get reviewed in.
If your child is asked out, I would recommend doing the practice assessment. DD found the two English practice pieces to be helpful in decreasing anxiety of knowing what to expect. As far as the math part goes, what grade are you hoping for admittance into? Our DD was given a math test that covered material she had done a couple of years ago, as well as material that she had skipped in a grade skip, so she did not do well on the math portion of the assessment, which was all basic math skills (DD is a 7th grader now)
DH went with her to the assessment day and said that the information given was very useful. I had gone with her to the family summit last year, so I had heard some of what they said then.
It was within 2 weeks of her assessment day that we heard the results. She has been accepted!
So now we just need to find jobs so we can relocate.
Hope this is helpful. I would also love to hear from anyone who is/was a Davidson family to hear from an insider how things go.
Good luck!