I'm using 20 PPM, 32.786Khz external crystal oscillator for RTC because of 20PPM I am getting 1.33 sec delay in RTC per day can please let me know to how to get accurate time in this same crystal

 

Xtal Oven. or a more accurate crystal.

Here is a 5ppm:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=300-8763-ND

 

THE_RB has a project that uses a PIC to tweak a crystal oscillator. Basically it adds or subtracts counts to tweak a crystal clock to exact specs. Come to think of it, his web site has some excellent pointers on exactly your query, including crystal ovens.

 

Romanblacks design is what I use for my xtal oven. (not plural, as I only made 1 )

 

I think this may be of some help, even if you do not use this chip
http://www.maxim-ic.com/app-notes/index.mvp/id/58

 

I'm using 20 PPM, 32.786Khz external crystal oscillator for RTC because of 20PPM I am getting 1.33 sec delay in RTC per day can please let me know to how to get accurate time in this same crystal

What pic you using? PIC24+ has a calibration register to fine tune your rtc.

 

Please do not shotgun posts all over the forums. The one in Homework Help is the active one.