r - load symbols using quantmod up to a specific date -

how load stock data of amzn not include stock prices after 2016-01-12?

the code load up-to-date stock prices getsymbols("amzn", auto.assign = false) want pretend today january 12th , eliminate prices after date. convenient way that?

myseries <- getsymbols("amzn", auto.assign = false)  t <- myseries['::2016-01-12'] 

an explanation of subsetting given here http://www.quantmod.com/examples/data/