When comparing sys_info in test...

only compare whether the saves are equal to 0
and not their actual values.

This allows one to compare against the binary database
which does not contain actual values of save.

test/posix/ptz.pass.cpp

@@ -29,10 +29,11 @@
 bool
 is_equal(date::sys_info const& x, date::sys_info const& y)
 {
+    using namespace std::chrono;
     return x.begin == y.begin &&
            x.end == y.end &&
            x.offset == y.offset &&
-           x.save == y.save &&
+           (x.save == minutes{0}) == (y.save == minutes{0}) &&
            x.abbrev == y.abbrev;
 }