ratrena
eka-rātreṇa — on the first night;
SB 3.31.2
pañca-rātreṇa — by the fifth night;
SB 3.31.2
eka-rātreṇa — in one night;
SB 8.24.17
rātreṇa — in a night;
SB 10.53.6