I heard a rabbi say that the greatest day is Shabbat and its bigger then Yom Kippur,why is that?I have noe source to reffer to other then That I heard it,so I write the question here,maybe someone else know about this.

Tu Bishvat this year is on January 25, the same as back in 2005 (5765). I thought the dates matched up exactly every 19 years.

Though it does seem that there was something wrong with the year 1973, since 19 years later doesn't match up.