diff --git a/core/main.mk b/core/main.mk
index 9eea513d6f..b91770b08b 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -44,11 +44,7 @@ BUILD_NUMBER_FILE := $(OUT_DIR)/build_number.txt
 .KATI_READONLY := BUILD_NUMBER_FILE
 $(KATI_obsolete_var BUILD_NUMBER,See https://android.googlesource.com/platform/build/+/master/Changes.md#BUILD_NUMBER)
 
-ifeq ($(HOST_OS),darwin)
-DATE_FROM_FILE := date -r $(BUILD_DATETIME_FROM_FILE)
-else
 DATE_FROM_FILE := date -d @$(BUILD_DATETIME_FROM_FILE)
-endif
 .KATI_READONLY := DATE_FROM_FILE
 
 # Pick a reasonable string to use to identify files.
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 00c5ed02f3..30890c0e0b 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -256,11 +256,7 @@ endif
 
 ifndef PLATFORM_SECURITY_PATCH_TIMESTAMP
   # Used to indicate the matching timestamp for the security patch string in PLATFORM_SECURITY_PATCH.
-  ifneq (,$(findstring Darwin,$(UNAME)))
-    PLATFORM_SECURITY_PATCH_TIMESTAMP := $(shell date -jf '%Y-%m-%d %T %Z' '$(PLATFORM_SECURITY_PATCH) 00:00:00 GMT' +%s)
-  else
-    PLATFORM_SECURITY_PATCH_TIMESTAMP := $(shell date -d 'TZ="GMT" $(PLATFORM_SECURITY_PATCH)' +%s)
-  endif
+  PLATFORM_SECURITY_PATCH_TIMESTAMP := $(shell date -d 'TZ="GMT" $(PLATFORM_SECURITY_PATCH)' +%s)
 endif
 .KATI_READONLY := PLATFORM_SECURITY_PATCH_TIMESTAMP
 
@@ -289,11 +285,7 @@ ifndef BUILD_DATETIME
   BUILD_DATETIME := $(shell date +%s)
 endif
 
-ifneq (,$(findstring Darwin,$(UNAME)))
-DATE := date -r $(BUILD_DATETIME)
-else
 DATE := date -d @$(BUILD_DATETIME)
-endif
 .KATI_READONLY := DATE
 
 # Everything should be using BUILD_DATETIME_FROM_FILE instead.