Holy Week Curiosity

I was thinking about Holy Week on my walk this morning. I know the significance of the days this week, but I never thought about WHEN people started respecting Holy Week like Christians do today.

How long after the Resurrection did Christains start observing these signifacnt days? How long have palms been given at Mass on Pam Sunday?

I am still searching; If anyone has anything to share, leave me a comment!
At present the best information I found was from the EWTN website. Some points of interest to me:

This week was held in great veneration even as early as the
third century, as we learn from St. Denis bishop of Alexandria, who lived at
that time. (3rd century! cool!)

In the following century, we find St. John Chrysostom,
calling it the 'Not,' says the holy doctor, 'that it has more
days in it than other weeks, or that its days are made up of more hours than
other days; but we call it , because of the great mysteries which
are then celebrated.' (what a great way to describe
it. apologetics)

We find it called also by other names: the (hebdomada poenosa)>, on account of the sufferings of our Lord Jesus Christ,
and of the fatigue required from us in celebrating them; the indulgence>, because sinners are then received to penance; and, lastly,
, in allusion to the holiness of the mysteries which are
commemorated during these seven days. This last name is the one under which it
most generally goes with us; and the very cars themselves are, in many
countries, called by the same name, Holy Saturday.>