For me it has been at least a couple months.

Depending on the leaf and the conditions it could take anywhere from 4 weeks to 6 months. The fresher the leaf and closer to the crown the faster propagation will occur.
Fred in NJ

ok , thanks for the replies. So its a waiting game.

Minal,
Whenever you put down leaves or baby plants, it is best to bag them for a greenhouse effect so that the root system is developing to its maximum capacity. I have found that when the starter plants/leaves are bagged, they produce earlier and healthier.

Dora

Hi Dora,
thanks for that tip. I have my leaves in a tray. I had removed the clear lid a few days ago because of too much water condensation, but I will put the lid back on. I have other leaves in strawberry plastic containers,will surely put those in a ziploc or plastic bag.
Minal.