Reminder to file form I-751

[Nadali 0]

Today I received reminder to file form I -751  during the 90 days and priority date 10/16/2019 .my GC will expire in 17-02-2020 . My question  should I send the file on 15-11-2019 as this will be 90 days or send the file this week .sorry I am confused any answers will help me thanks.

[Georgia16 2,858]

14 minutes ago, Nadali said:

Today I received reminder to file form I -751  during the 90 days and priority date 10/16/2019 .my GC will expire in 17-02-2020 . My question  should I send the file on 15-11-2019 as this will be 90 days or send the file this week .sorry I am confused any answers will help me thanks.

You should sent it within that 90 day period. 
so the window opens 90 days before your GC expires. It is recommended to sent it as early as possible in the 90 day window as they are backlogged with ROC. 
if they receive the ROC package just one day before your window they will return it to you.