diff --git a/libc/docs/date_and_time.rst b/libc/docs/date_and_time.rst
--- a/libc/docs/date_and_time.rst
+++ b/libc/docs/date_and_time.rst
@@ -41,7 +41,7 @@
 clock_settime
 ctime
 ctime_r
-difftime
+difftime              |check|
 getdate
 gmtime                |check|
 gmtime_r              |check|
diff --git a/libc/src/time/difftime.h b/libc/src/time/difftime.h
--- a/libc/src/time/difftime.h
+++ b/libc/src/time/difftime.h
@@ -1,5 +1,4 @@
-//===-- Implementation header of difftime -------------------------*- C++
-//-*-===//
+//===-- Implementation header of difftime -----------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
diff --git a/libc/src/time/difftime.cpp b/libc/src/time/difftime.cpp
--- a/libc/src/time/difftime.cpp
+++ b/libc/src/time/difftime.cpp
@@ -1,5 +1,4 @@
-//===-- Implementation of difftime function
-//---------------------------------===//
+//===-- Implementation of difftime function -------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.