How should I say something happens at regular intervals?

Question

For example, how would I translate a phrase like “I like to eat something every 4 hours”? I have heard two ways of phrasing this in Esperanto:

• Mi ŝatas manĝi ion ĉiujn 4 horojn (this is similar to the English way)
• Mi ŝatas manĝi ion ĉiun 4an horon

Are both of these correct? Or is there a better way to phrase this? Maybe even something like:

• Mi ŝatas manĝi ion po unu fojo en 4 horoj

Answer 1

The second option seems to me to be clearer than the first, as the first one could technically also mean that you like to eat somthing for all the four hours (of some four-hour period known in the context of utterance). The third option is also correct and clear, though rather uncommon, probably because it is unnecessarily complex.

So I would recommend:

Mi ŝatas manĝi ion ĉiun kvaran horon.