If we do not account the first punishment in 1313 BCE, then the first punishment would be the destruction of the first Temple by Babylon. The First Temple was totally destroyed by the Babylonians in 586 BCE (425 BCE according to historical Jewish sources). To make seven times punishments complete we need indeed seven punishments.
I think that the first in 1313 BCE doesn't count because the Israelites didn't get into the promised land yet, and after believing the spies instead of their God, they were punished with another 38 years of dwelling in the desert. In Leviticus 25:1 we read before God mentioned the seven punishments: "And the LORD spake unto Moses in mount Sinai, saying, 2 Speak unto the children of Israel, and say unto them, When ye come into the land which I give you, then shall the land keep a sabbath unto the LORD." 
ect...

God's punishment would lead them being removed from the LAND, THE CITIES AND TEMPLE (SANCTUARY) BEING DESTROYED, AND SCATTERED THEM THROUGHOUT THE NATIONS if they didn't follow God's laws and commandments once they set foot in the Promised land. In this case the first punishment occured in 1313 BC could probably be out of question.  

​

Option one: If we can rely on previous view, then we still got six punishments and a seventh to come after WWII. Could this 7th date be in the very near future? Note that this concerns a personal view and doesn't mean to be correct. But i feel there's some connection. 

Option two: On the other sight it also could be meant 7 times according to: a time for one year or 360 x seven is 2520 yrs of punishment or sevenfold which is seven times.

In option two we start with the first destruction of the Temple in 586 BC + 2520 years of punishment which brings us into the year 1934 as being the last punishment. 
In 1934 Nazi Germany came into power and undeniably the most worst thing that this people were about to undergo in their whole history until 1947/1948 when Israel finally got her identity back as people and as a nation as well. But regarding my opion it doesn't mean that God's last wrath won't come upon Israel. There is still a punishment to come in the last days as Revelation and other prophets state in their prophecies, and that's why option one seems more acceptable, but that's only my opinion at this very moment. 
Meanwhile on the internet, i found a very good study about option two and seems very acceptable... !
http://freepages.religions.rootsweb.ancestry.com/~jimmylewis/PunishmentLev26.htm

​

Anyway, the signs i researched according to Rev 15 are speaking for themselves!

Could the 9th of Av, Tisha b'Av refer to a beginning of troubles or a final end? Could it be related to some rapture when we think about the ten virgins and their oil lamps? I do not dare to confirm any of these possible events, but according to 'A time of mourning, a time of hope' regarding this 9th of Av, it possible could be linked to these possible events to come.

​

THE POSSIBLE REVELATION 15 SIGN: