Oracle Package equivalent in Postgres

[Firthouse banu <penguinsfairy@xxxxxxxxx>]

Hi Postgres master minds, 

Am currently working on migrating databases from  oracle to Postgres. 

Am going to work on crons and packages in oracle which needs to be converted in Postgres. How to convert package in oracle to Postgres. Is there any equivalent in Postgres if not how it works in Postgres. 

Eagerly  waiting for replies. 

Thanks