Employee's Providents Fund Organisation [EPFO] — Leave conversion

Address:

Indore, Madhya Pradesh

My collegue was on EOL from 01/12/2016 to 31/12/2016.After this spell from 01/01/2017 to 15/01/2017 she was on earned leave. she joined the duty after 01/12/2016 on dated 16/01/2017.
Further on 13/02/2017 she applied for leave conversion of EOL for the period 01/12/2016 to 31/12/2016 into leave not due. But my employer rejected his application on the basis that she applied after 30 days of expiry of EOL.

Is it right or wrong. whether leave conversion period treated from 01/01/2017 which is the date of expiry of EOL or from 16/01/2017 which is the date of joining after expiry of EOL and EL also.