Bootstrap v2.3 collapse and data-parent

Question

i'm using Php 5.3 symfony 2 and Bootstrap v2.3

i wanna do an accordion like this (Bootstrap 3) :

http://jsfiddle.net/jvx7oven/

But i'm using Bootstrap v2.3 and the #data-parent attribute doesnt work..

i wanna do a 3 level accordion and all elements closed when one of the collapsible item is shown.

Note: The data-parent attribute makes sure that all collapsible elements under the specified parent will be closed when one of the collapsible item is shown.

Please help me , i did it with Bootstrap2 in this fiddle :

https://jsfiddle.net/umjmb33n/

But the third level "MONTH" doesnt closed when one is shown..