I agree with Symandinome, it could be a date of some sort, I looked up the date 1. June, heres the link:
http://en.wikipedia.org/wiki/June_1 , you can also research other dates because it may not be the correct date, it may be 16. July or January 6th, and I also looked into the year 1670, the link:
http://en.wikipedia.org/wiki/1670 , you might find nothing related to you but you might find something important none the less, it may be family related so I suggest you ask relatives about it in case they know something, hope you find your answer soon
