Roman and Indian Ancestor Worship: Points to an Indo-European Prototype?

[Materialist]

To introduce myself, after learning of my Indian ancestry, I began studying the Vedic form of Hinduism and have totally converted to the Grhya type, which is what non-brahmins practiced. Well, it's mostly ancestor worship, and it reminded me of something I read about Roman religion, so I looked at the Nova Roma website for their articles on the Lares.

The similarities I found in dating the times for these respective cultures' ancestor rites made me ask if they could date back to the Indo-European period.

The Indians, like the Romans, originally had a lunar calendar, with a month starting around the new moon. Both cultures had rites for the Lares/Pitrs on the start of the month and on the full moon. The difference being that the third offering to these beings was on the first quarter for the Romans and around the last quarter for the Indians.

So, that has made me wonder if these ancestor rites date back to an original in an Indo-European past, and if there were originally three monthly rites to perform, or just two, and the first/last quarter one came later (parallel evolution, as it were), which is why there's a difference?

What does everyone else think?

[Heliocoptero]

So, that has made me wonder if these ancestor rites date back to an original in an Indo-European past, and if there were originally three monthly rites to perform, or just two, and the first/last quarter one came later (parallel evolution, as it were), which is why there's a difference?

Could be a simple coincidence. If you have a lunar calendar, the phases of the moon naturally become important moments and those are usually marked by religious and/or family occasions. But I wouldn't rule out a common Indo-European origin entirely.