JolibeeFlyer,
they normally post the list of applicants in the bulletin board for everyone's comments, etc... Last Friday, they called in 8 for initial interview. Now, I don't know if this 8 was on the list posted three weeks ago. Now, if they were, then next month, more than likely they will call in more for August, so on and so forth. I do believe they are pooling the F/O applicants since they are 'easier' to find. Not unlike for ATR Captains.
When they do call you, they will offer a date for initial interview. Tell them if you can make it or not. Offer an alternative date closest to what they gave. If okay with them, then good for you. On day of meeting, if they like what they see and hear, then expect to spend more time in being around their offices than just for the initial meet. If they need more requirements from you, then thats a good indication.
I hope this helps somehow.
good luck!