compat: Update forward compatibility horizon to 2021-09-01

PiperOrigin-RevId: 394181184
Change-Id: If9f26b0a5697a83091f0b4a226393eefba5e7e07

Author: tensorflower-gardener

tensorflow/python/compat/compat.py

@@ -33,7 +33,7 @@
 # This value changes every day with an automatic CL. It can be modified in code
 # via `forward_compatibility_horizon()` or with the environment variable
 # TF_FORWARD_COMPATIBILITY_DELTA_DAYS, which is added to the compatibility date.
-_FORWARD_COMPATIBILITY_HORIZON = datetime.date(2021, 8, 31)
+_FORWARD_COMPATIBILITY_HORIZON = datetime.date(2021, 9, 1)
 _FORWARD_COMPATIBILITY_DELTA_DAYS_VAR_NAME = "TF_FORWARD_COMPATIBILITY_DELTA_DAYS"
 _FORWARD_COMPATIBILITY_DATE_NUMBER = None