From: David MacMahon <davidm@...>
Date: 2013-02-13T02:56:04+09:00
Subject: [ruby-core:52161] Re: [ruby-trunk - Bug #7829] Rounding error in Ruby Time


On Feb 12, 2013, at 12:51 AM, loirotte (Philippe Dosch) wrote:

> Improve the documentation makes sense, but is there really a good reason to floor this value instead of rounding it? I'm searching for examples where floor could be interesting, but I don't see any.

IMHO, using floor when reducing the precision of a time representation is the appropriate thing to do to avoid "time travel" into the future.  One real world reason for this has to do with timestamps of files.  Consider a file stored on a filesystem that supports lower than native timestamp precision.  If the filesystem were to round the time rather than truncate it then it would be possible for files to be timestamped with future times which can defeat/confuse tools that compare timestamps.

Dave