Commitment Un-Reservation & Obligation Reservation for PR/PO on GL Dates specifically

Hi Experts,

Can you please advise on the below Questions

1.I have created PR with GL date= 15-Dec-2016, Then PO got Auto created with GL Date = 10-Jan-2017

My Question:  Once the PO is autocreated, will the Commitment get un-reversed on the same GL date where PR was created i.e 15-Dec-2016

or Will the Commitment get Un-reversed on the GL date where the PO is created i.e 10-Jan-2017

2. PR got created with the below 3 Lines with Future date

Line-1 GL date 10-Dec-2017                           Amount =10000

Line-2 GL Date 10-Jan-2018                           Amount =12000

Line-3 GL Date 10-Jan-2019                           Amount =14000

PO got Auto created & User has changed the GL date as stated below