* Canonicalise timestamps in the Nix store to 1 (1970-01-01 00:00:01

UTC) rather than 0 (00:00:00).  1 is a better choice because some
  programs use 0 as a special value.  For instance, the Template
  Toolkit uses a timestamp of 0 to denote the non-existence of a file,
  so it barfs on files in the Nix store (see
  template-toolkit-nix-store.patch in Nixpkgs).  Similarly, Maya 2008
  fails to load script directories with a timestamp of 0 and can't be
  patched because it's closed source.

  This will also shut up those "implausibly old time stamp" GNU tar
  warnings.

doc/manual/writing-nix-expressions.xml

@@ -1432,7 +1432,7 @@ command-line argument.  See <xref linkend='sec-standard-environment'
   inputs.</para></listitem>
 
   <listitem><para>After the build, Nix sets the last-modified
-  timestamp on all files in the build result to 0 (00:00:00 1/1/1970
+  timestamp on all files in the build result to 1 (00:00:01 1/1/1970
   UTC), sets the group to the default group, and sets the mode of the
   file to 0444 or 0555 (i.e., read-only, with execute permission
   enabled if the file was originally executable).  Note that possible

src/libstore/local-store.cc

@@ -153,7 +153,7 @@ void canonicalisePathMetaData(const Path & path, bool recurse)
         if (st.st_mtime != 0) {
             struct utimbuf utimbuf;
             utimbuf.actime = st.st_atime;
-            utimbuf.modtime = 0;
+            utimbuf.modtime = 1; /* 1 second into the epoch */
             if (utime(path.c_str(), &utimbuf) == -1) 
                 throw SysError(format("changing modification time of `%1%'") % path);
         }

src/libstore/local-store.hh

@@ -190,8 +190,8 @@ void copyPath(const Path & src, const Path & dst);
 
 /* "Fix", or canonicalise, the meta-data of the files in a store path
    after it has been built.  In particular:
-   - the last modification date on each file is set to 0 (i.e.,
-     00:00:00 1/1/1970 UTC)
+   - the last modification date on each file is set to 1 (i.e.,
+     00:00:01 1/1/1970 UTC)
    - the permissions are set of 444 or 555 (i.e., read-only with or
      without execute permission; setuid bits etc. are cleared)
    - the owner and group are set to the Nix user and group, if we're