High-Level Timeline

(plus) September thru the end of October - Plan, create/update test scripts in ALM, move pending support & project work into production.
(green star) 10/12/2017 - SAP release of year end base level support pack
(tick) 10/19/2017 - Last date to implement support & enhancement changes until freeze ends on 12/13/2017
(tick) 10/20/2017 - Development Freeze begins
(tick) 10/23/2017 - End of day production snapshot to be used to refresh test environments (9/25 for SF3)
(info) 10/25/2017 - Unit test

(info) 11/02/2017 - 11/03/2017 Controlled Payroll Runs (SH2)

(info) 11/06/2017 - System Integration Test (regression test fixes: 11/29-30/2017)

(warning) 12/08/2017 - Go-live weekend! (start Friday at 5pm)

(info) 12/13/2017 - Development Freeze ends

(big grin)