te tikanga
1. supposedly, it would seem, strictly speaking, by rights, it's supposed to be like this - an idiom used to make an assertion or to state that something was supposed to take place or have taken place.
I te mea he hararei tūmatanui te Paraire, ko te tikanga ka tīkina mai ngā rāpihi i te ata o te Rāhoroi (HKK 1999:152). / Because Friday is a public holiday, the rubbish is supposed to be collected on Saturday morning.