"Ronen Hefetz" wrote:
I tried =MEDIAN(IF(I2:I50<M1,J2:J50)), but that is
returning the median of all values, whether or not
the corresponding value in column J is prior to the
date in M1.

That would be the case if I2<M1 by coincidence and you simply pressed Enter
instead of ctrl+shift+Enter.

The above formula should be entered as array formula.

Enter an array formula by pressing ctrl+shift+Enter instead of Enter. Excel
will display an array formula surrounded by curly braces in the Formula Bar,
i.e. {=formula}. You cannot type the curly braces yourself. If you make a
mistake, select the cell, press F2 and edit, then press ctrl+shift+Enter.

While pressing and holding Ctrl and Shift, press Enter. Then release all
three keys.