Resolves SF bugs 697989, 697988, 697986.
\modulesynopsis{Time access and conversions.}
-This module provides various time-related functions.
-It is always available, but not all functions are available
-on all platforms.
+This module provides various time-related functions. It is always
+available, but not all functions are available on all platforms. Most
+of the functions defined in this module call platform C library
+functions with the same name. It may sometimes be helpful to consult
+the platform documentation, because the semantics of these functions
+varies among platforms.
An explanation of some terminology and conventions is in order.