Sacred Heart Of Jesus Feast Day - 16 June

Quoted from Learn Religions [1]:

The date of the Feast of Corpus Christi was set at the request of Christ Himself, Who appeared to St. Margaret Mary Alacoque on June 16, 1675.

The Feast of the Sacred Heart of Jesus is celebrated on the Friday after the octave (eighth day) of the Feast of Corpus Christi. The traditional date of Corpus Christi is the Thursday after Trinity Sunday, which falls one week after Pentecost Sunday. Thus, the Feast of the Sacred Heart of Jesus falls 19 days after Pentecost, which is seven weeks after Easter.

In those countries, such as the United States, where the celebration of Corpus Christi is transferred to the following Sunday, the Feast of the Sacred Heart is still celebrated 19 days after Pentecost.

Since the date of Pentecost Sunday depends on the date of Easter, which changes every year, the Feast of the Sacred Heart falls on a different date each year as well.

[1] https://www.learnreligions.com/when-is-the-feast-of-the-sacred-heart-541617, quoted without hyperlinks.