Upcoming Due Dates for GST filings

Please note that due Dates for GSTR-1 is as follows:

(For Assessee having opted for monthly option. Of filing)
April-2018  31.05.2018
May-2018  10.06.2018
June-2018  10.07.2018

Due Dates for GSTR-3B is as follows:

April-2018  20.05.2018
May-2018  20.06.2018
June-2018  20.07.2018

Till now GSTR-3B was filled first and then GSTR-1 however for May and June before filling of GSTR-3B on 20th we need to upload details of Sales in GSTR-1 by 10th.