Ideally, Pratikraman is considered due as soon as a there is a lapse in observing any of the 12 vows . Sooner we ask forgiveness for the lapse, minimal would be the bondage of the Karma.
However as a layman we may not realize immediately about any such mistake that we commit and since we are likely to faulter every now and then, it is laid down that we should do Pratikraman twice a day.
There are 5 types of pratikaman based of when it should be done :
One is called Evening(Devashi) Pratikraman, which is meant for the lapses during the day time and should be done at the end of the day, at sunset.
The other known as Morning (Rai or Raishi)Pratikraman is meant for lapses during the night time and should be done in the morning at sunrise.
The intention in laying down two Pratikramans a day is that a person can easily recall the lapses or transgressions in which he might have indulged during that particular day or night. He can therefore seek forgiveness for the same without involving undue delay.
Many people, however, think that they cannot spare that much time every day. Such people should do Pratikraman at least once every fortnight. This is known as Fortnightly (Pakshik)Pratikraman.
There are some people who think that they cannot spare even that much time.Such people should do at least one Pratikraman every four months, known as Four Monthly(Choumasi) Pratikraman.
There are many people who think that they cannot spare even that much time. All of them must do at least one Pratikraman every year. This Yearly(Samvatsari) Pratikraman is considered a must for every Jain.