show previous date data

[raven1001]

I got 1 question here. How can I retrieve the value from the previous date?

For example if today is 1st of March, so the page will automatically show 29 February's value.

And everyday if I go to this page, then the page will show me the previous data which is yesterday data.

[mrhappiness]

if php only:
- calculate last day's date
- open file named like that

if php/mysql
- select data where date = now() - interval 1 day

if not suitable: provide more information