Duration of stay with a Singapore Tourist E visa

I have a Singapore evisa in a PDF file with a two month validity. From what I understand all I need to do to enter Singapore is to present a print out of this PDF file. However there is no mention about how long I'm allowed to stay in Singapore And from what I understand it is completely dependent on the immigration authorities how long they let me stay. I planned to stay for 11 days And was wondering how I would book my hotel if I am not sure as to how long I would be allowed in for?