Ltcg investment due date u/s 54f when no cgas opted and 54ec

Quoting from Section 54F:
The amount of the net consideration which is not appropriated by the assessee towards the purchase of the new asset made within one year before the date on which the transfer of the original asset took place,

or which is not utilised by him for the purchase or construction of the new asset before the date of furnishing the return of income under section 139, shall be deposited ....... (in CGAS)

Scenario:
Long term capital asset (NOT house property) transferred on:
30/03/2017 (FY 16-17)

Questions:
[1] So, the time limit to invest the LTCG in house property u/s 54F without depositing in CGAS is?
Is it the return due date u/s 139 i.e., 31st July 2017 ?

[2] and, the time limit to invest the LTCG in 54EC bonds is?
Is it the return due date u/s 139 i.e., 31st July 2017 ?

[3] What does "date of furnishing the return of income under section 139" mean? due date?