It has been a long time that people are requesting these two features again and again.
1)GTC order : Everytime we get a same rhetoric answer from zerodha ‘’ we have to build like our own layer to maintain’.
2)Margin for 2-3 days: Zerodha provides margin for intraday only whereas some brokers are providing two or three days.
Now please provide these features or tell us how much time it will take? One month or one year or five year? Be honest. Thank you
These Margin Positions have made Nifty Monkey. 
Give Them some time.
Adding New features in existing Infrastructure is not a cake walk.
It takes Time, BackTest, Error detection, backup, machine compatibility, platform independent, bug free working, availability, user interface, frames connectivity, data mining, network connectivity, http encryption over SSL ipv4 & ipv6 etc etc…
There are Already many bugs in existing systems Like, there server get down sometimes, order not get placed, Order modification fail, auto square off orders. Etc etc…
They should 1st make the existing Infrastructure bug free then only add new features.
It’s Just Like you want to Run bullet train on existing Indian railways Tracks. We all know the consequences.
This features are provided mostly by banks.
They charge more brokerage as well as interest on the margin used by The trader s and investors.
Zerodha can provide this type of service if they’re collaborate with other financial institution .
It will require huge capital because maximum trading happen through Zerodha.
This facility is really enjoyed by The traders on other broking terminals
Its unfair to expect overnight margin facility from zerodha. Overnight margin position may increase the risk of loosing huge money with any unwanted incident happening overnight and few inexperienced person are sufficient to put the stake of others in danger. So request zerodha not to include such a feature as the fee charged by them is not even comparable by what is charged by full time brokers. ( 20 by zerodha where icici reliance iifl gnp paribas usually charge 500+ for even a small trade)
One can always switch to a broker kyun ki aap chane ke daam me badaam nahi khareed sakte
For GTC i agree with the rest of the people that having it will be beneficial as it will put an end to daily placing of orders.
Sir aap to badi jaldi uth gaye 
market ka kamaal 
Zerodha has got NBFC license recently. You can expect it soon.
i am highly satisfied with service for the service that zerodha is providing.
As @Tapovan_Vashisht_Vik sir told is correct word by word.
many times other terminals gives opportunity for the positional traders to exit in profit due to this type of facilities.
As zerodha has excellent service in many point of view ,some traders or investors are not trading with zerodha due to the lack of this facilities.
For competing with other brokers it can be considered.
Those traders or investors who want to take risks they can avail this facility otherwise we should cut our coat according to our cloth and follow the disciplines strictly.