Welcome back!
To answer your question, it could be days, months, years or never. We really don't know what is going on in their little brains so who knows for sure.
In general, it is generally 6 months to 1 year from the time they are fully matured. Watch for the male cleaning several spots repeatedly...then cleaning only one over and over again. That is a good sign that they have chosen a spot and he is getting it ready for eggs.
If you think your clowns are mature enough, you may want to try laying a small ceramic tile at or near the base of their anemone with rough side out. Place it at an angle. They seem to like these and may choose it as a spot to lay eggs. Do this befor ethey choose a spot. Usually once they choose a spot, they don't choose another one readily so pick one that you can quickly replace with an identical tile if you want to try and raise the fry. If their spot vanishes completely for more than a day, they may take up to a year to choose another one so this makes moving a rock with eggs on it tricky.
Joyce Wilkersons book "Clownfishes" is a great resource for raising and breeding clownfish...and just keeping clowns in general.
Hope this helps.
