The only relevance Tu B'Av has for me, as far as I can think of, is that we do not say Tachanun on Tu B'Av.

There seems to be a machlokes between Rav Shteinman and Rav Chaim Kanievsky about when people should start their vacations, specifically travelling around the country to go camping or stay in hotels and cottages...

Ladaat quotes Rav Shteinman as saying that people should not go away for vacation - the yetzer ha'ra does not take vacation, so anybody who can do without it, should. As well, if going out, people should be very careful about safety. People say it wont happen to them, but there are many accidents and tragedies that happen with water. He says the Chazon ish says the sea is important and was created for those who learn Torah, but the Chazon Ish never said one must go in to the water.  Also, he would say the benefit of going to the sea is for up to 10 minutes - beyond that adds nothing. Rav Shteinman said that when his kids were young he would take them on vacation to visit the Kotel and to visit the grave of Rabbi Shimon bar Yochai in Meron.

Kikar quotes Rav Kanievsky as saying that people should not go away on vacation until after 15 Av. His rationale is that Shulchan Aruch says when the month of Av is brought in, one should minimize his simcha. This applies, Rav Kanievsky says, until the 15th of Av. As well as vacations, one should avoid renovations on his house until 15 Av as well as buying real estate.

15 AV is today, so from now you can enjoy your vacation... unless you hold like Rav Shteinman...

This Shabbos is Tu B'Av - the 15th day of Av, which the Mishna describes as being of the happiest days of the year, for a number of reasons. In the days of yore, the maidens would prance in the fields and vineyards (how do you like that description?) while the young men would select their wife.

In modern day Israel, the day has become adopted as a Jewish form of Valentine's Day.

The funny thing is, despite the criticism some among the religious have for the secular having turned the day into a day of love and Hallmark greeting cards, other than making it into a Valentine's Day, there would be no modern day mention of Tu B'Av at all. We, the religious, do not celebrate it in any way other than by skipping tachanun during davening.

Why we have abandoned the old customs of celebrating Tu B'Av I do not know. Perhaps it is because in todays age of hyper-tznius, it just would not work in any way.

I think we have to thank the secular for keeping this holiday, in name at least, alive for us.