Get yesterday date PHP

Here is the different way of Getting yesterday date with PHP
using strtotime() and mktime()  we can find the previous date in easy way.

# Using strtotime() function
// from Current Date
echo date("d-m-Y",strtotime("yesterday"));

# Using mktime() function
// from Specific date  eg: Oct-01-2011
echo date("d-m-Y",mktime(0,0,0,10,1,2011)-1);


Output:
13-09-2011
30-09-2011