Programmatically access Currency Exchange Rates from Yahoo Finance by Date
I found the answer to this question VERY useful, but I would like to also get exchange rates for dates in the past, not just today's exchange rates. I'm writing an iPhone app that uses the exchange rate to calculate money made from sales in different countries.
Here's the example from the answer mentioned above to get today's echange rate for GBP to EUR: http://download.finance.yahoo.com/d/quotes.csv?s=GBPEUR=X&f=sl1d1t1ba&e=.csv
Does anyone know how to do this for any other dates? THANK YOU!
Answer
To retrieve historical data of currency exchange rates, you can't use Yahoo Finance. Their API only offers historical data of stocks. For example for APPLE between April the 1st 2003 and July, 30:
http://ichart.finance.yahoo.com/table.csv?s=AAPL&a=3&b=1&c=2003&d=6&e=30&f=2003&g=d&ignore=.csv
So, in your case you need to dig somewhere else. The only other main API available is OpenExchangeRate: http://openexchangerates.org/documentation#historical-data
Notice:
Important: From end August 2012, you will need an App ID to query the Open Exchange Rates API - it's free for personal use, and cheap for apps and commercial uses.
Other option:
You could use this: Free Forex Historical Data and then use Yahoo Finance (Currency Rates) each day (at your convenience) to construct an up-to-date table with all your currencies rates needed.
EDIT
The FED offers you historical data of many currencies rates. See Data Download Program to retrieve (csv, xls, xml) historical data. You can adapt it to your needs.