time/ISO8601: allow omitting the "Z" suffix

And allow "Z" suffix after date.

NEWS

@@ -1,6 +1,7 @@
 ver 0.21.17 (not yet released)
 * protocol
-  - relax the ISO 8601 parser: allow omitting the time of day
+  - relax the ISO 8601 parser: allow omitting the time of day and the "Z"
+    suffix
 * archive
   - zzip: improve error reporting
 * outputs

src/time/ISO8601.cxx

@@ -83,7 +83,7 @@ ParseISO8601(const char *s)
 	/* parse the time of day */
 	if (*s == 'T') {
 		++s;
-		end = strptime(s, "%TZ", &tm);
+		end = strptime(s, "%T", &tm);
 		if (end == nullptr)
 			throw std::runtime_error("Failed to parse time of day");
 
@@ -93,6 +93,9 @@ ParseISO8601(const char *s)
 
 	auto tp = TimeGm(tm);
 
+	if (*s == 'Z')
+		++s;
+
 	if (*s != 0)
 		throw std::runtime_error("Garbage at end of time stamp");
 

test/TestISO8601.cxx

@@ -51,6 +51,12 @@ static constexpr struct {
 	{ "2019-02-04", 1549238400, std::chrono::hours(24) },
 	{ "2018-12-31", 1546214400, std::chrono::hours(24) },
 	{ "2019-01-01", 1546300800, std::chrono::hours(24) },
+
+	/* date with time zone */
+	{ "2019-02-04Z", 1549238400, std::chrono::hours(24) },
+
+	/* without time zone */
+	{ "2019-02-04T16:46:41", 1549298801, std::chrono::seconds(1) },
 };
 
 TEST(ISO8601, Parse)