When you import a calendar into  as an  file, you get a static calendar that doesn't update until you manually import a new version of the ICS file. However, if the owner of the calendar has published the ICS file online, you can subscribe to the online calendar, known as an . When you subscribe to an iCal, the events that you see in the calendar are updated whenever the owner of the iCal makes changes, so that you always have an up-to-date version of the iCal.
Ko v  uvozite koledar kot datoteko , dobite statični koledar, ki se ne posodablja, dokler ročno ne uvozite nove različice datoteke ICS.  Toda če je lastnik koledarja objavil datoteko ICS v spletu, se lahko naročite na spletni koledar, ki se imenuje . Ko se naročite na koledar iCal, so dogodki, ki jih vidite v koledarju, posodobljeni vsakič, ko lastnik koledarja iCal naredi spremembe, tako da imate vedno posodobljeno različico koledarja iCal.