I am looking to create a simple graph showing 2 numbers of time for my personal twitter. They are:

Number of followers per day
Number of mentions per day

From my research so far, the search API does not provide a date so I am not about to do a GROUP BY. The only way I can have access to dates is through the OAuth Api but that requires interaction from the end user which I am trying to avoid. 
Can someone point me in the right direction in order to achieve this? Thanks.
The best way is to use a cron to record the data daily.
However, you can query the mentions using the search api with a untill tag. Which should do the trick.
Twitter API: Getting Data for Analytics