How to change the date to 1 day ago

First you need to get an idea of ​​a given date as a class object that is designed to work with dates. This class is the Calendar class.

Get an instance of the Calendar class:

 Calendar calendar = Calendar.getInstance(); 

Create an object that converts the date as a string (of a specific format) into a Date object:

 SimpleDateFormat sdf = new SimpleDateFormat("dd.MM.yyyy"); 

Get the object of class Date from your string and initialize it with calendar :

 calendar.setTime(sdf.parse(date)); 

Change the calendar object by decrementing the date:

 calendar.add(Calendar.DATE, -1); 

You get the text view of the calendar object:

 date = sdf.format(calendar.getTime());