Robinson Crusoe

If something can be used "at any time", what does that actually mean?

Abilities and effects that say they can be used at any time can be used at any time! You can invoke an ability, for instance, after rolling dice or drawing a card, but before resolving the results of that roll or draw. The only limitation is that you can't rewind time: you can't change your mind about something you've already done in order to squeeze in the use of an ability that you didn't want to use until just now!