From length of time, all things are presumed to have been done in due form.

Explanation

Where an act has stood unchallenged for a great length of time, the law presumes that all necessary formalities were observed in its execution.

Where this applies

• This arrangement has been in place for decades so it should be presumed valid.
• An old deed was executed so long ago that proper formalities should be assumed.
• Nobody challenged this for generations so the law should presume it was done right.