placement of prochaine

Question

why "la semaine prochaine" but "ta prochaine soirée costumée? (why not "ta soirée costumée prochaine"?)

Maarten Kamp · Accepted Answer

Cindy, 
see previous remarks from Cécile about the positioning of prochain/e when referring to an ‘ event ‘ ( la prochaine soirée costumée) rather than a ‘ duration/time period ‘ ( la semaine prochaine ) per se. 
https://french.kwiziq.com/questions/view/where-to-put-prochain-e
Other previous discussion worth looking at :
https://french.kwiziq.com/questions/view/i-don-t-understand-why-prochain-comes-before-cours-as-it-doesn-t-seem-to-fit-with-the-group-of-adjec#:~:text=Kwiziq%20community%20member-,I%20don't%20understand%20why%20'