dnd 5th – How often can spells be cast from a vigilance rod?

One of the characteristics of the cane of vigilance allows the wearer to cast a number of spells:

While holding the rod, you can use an action to cast one of the following spells: detect evil and good, detect the magic, detect poison and disease, or see invisibility.

Unlike many other magic items that can be used to cast spells, there is no text indicating how often these spells can be used. Does the absence of any declared limit mean that these spells can be cast from the cane any number of times, effectively turning them into reinforcements for the cane bearer?