I’m sure that this is 100% possible, it just might be a bit hard to observe the effects. Effecting the present and future are very easily achievable with basic magickal techniques, and as far as I’m concerned past life regression, certain forms of soul travel, and remote viewing are all forms of effecting or at least tapping into the past. I know that current time can also be altered through servitors so I’m sure that one can effect the past if created for that purpose, but again, it might be hard to verify the results unless you can also tap into the alternate reality that splinters off from it.
Another thought, if your goal is to deliver certain information to yourself in the past, that at least implies that you already have that information now. Which could lead to two possibilities;
- You wouldn’t really need to perform this ritual because you already possess the information you want and can just proceed with life now having it.
- You already performed the ritual, your past was effected, thus the reason you have the information now, and you are already living in the weird time-space continuum loop of your own magick haha.