St. Valentine’s Day VS. Hag Ha’ahava

Saint Valentine, officially known as Saint Valentine of Rome, is a third-century Roman saint widely celebrated on February 14 and commonly associated with "courtly love. Quite surprisingly, Valentine’s Day resembles in some ways the upcoming Jewish festival of the 15th of Av (Tu B’Av).
And so, we’ve decided to perform a little research about the origin of Valentine's Day and inform you how a version of this holiday is mentioned and celebrated in Israel:

One common story about St. Valentine is that in one point of his life, as the former Bishop of Terni, Narnia and Amelia, he was on house arrest with Judge Asterius. While discussing religion and faith with the Judge, Valentine pledged the validity of Jesus. The judge immediately put Valentine and his faith to the test in which Valentine succeeded in restoring a child's vision an act that made Judge obey all of Valentine's requests.
However, other tales of St. Valentine's life claim he was executed either in the year 269, 270, 273 or 280. Other depictions of St. Valentine's arrests tell that he secretly married couples so husbands wouldn't have to go to war.

The romantic nature of Valentine's Day in Christianity may have derived during the Middle Ages, when it was believed that birds paired couples in mid-February. According to English 18th-century antiquarians Alban Butler and Francis Douce, Valentine's Day was most likely created to overpower the pagan holiday, Lupercalia.

In Israel there is a day called "yom ha'ha'ava",Tu B'Av (Hebrew: ט"ו באב, the fifteenth of the month Av (August)) is a minor holiday in the Hebrew calendar. While in the days of the Temple there was once many religious customs for this holiday, today there are no special religious customs, apart from the omission of Tachanun (a penitential prayer) after the morning and afternoon prayer services. In modern-day Israel, it is seen as the holiday of love (Hebrew: חג האהבה‎, Hag HaAhava) and known as the "Jewish Valentine's day"

So although the exact origin of the ‘Love holiday’ changes among Judaism and Christianity, it’s pretty clear that this date is widely recognized as a day for love, devotion and romance.