From b0a0583a35e95bbce3a9b4956ccc4b605b7baaec Mon Sep 17 00:00:00 2001
From: John Kerl <kerl.john.r@gmail.com>
Date: Tue, 17 Jan 2017 22:06:09 -0500
Subject: [PATCH] split out mlrdatetime from mlrutil to ease iterative windows
 port

---
 c/lib/mlrdatetime.c | 33 +++++++++++++++++++++++++++++++++
 c/lib/mlrdatetime.h | 14 ++++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 c/lib/mlrdatetime.c
 create mode 100644 c/lib/mlrdatetime.h

diff --git a/c/lib/mlrdatetime.c b/c/lib/mlrdatetime.c
new file mode 100644
index 000000000..20be36671
--- /dev/null
+++ b/c/lib/mlrdatetime.c
@@ -0,0 +1,33 @@
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#include "lib/mlrdatetime.h"
+
+// ----------------------------------------------------------------
+// seconds since the epoch
+double get_systime() {
+	struct timeval tv = { .tv_sec = 0, .tv_usec = 0 };
+	(void)gettimeofday(&tv, NULL);
+	return (double)tv.tv_sec + (double)tv.tv_usec * 1e-6;
+}
+
+// ----------------------------------------------------------------
+// See the GNU timegm manpage -- this is what it does.
+time_t mlr_timegm(struct tm* ptm) {
+	time_t ret;
+	char* tz;
+
+	tz = getenv("TZ");
+	setenv("TZ", "GMT0", 1);
+	tzset();
+	ret = mktime(ptm);
+	if (tz) {
+		setenv("TZ", tz, 1);
+	} else {
+		unsetenv("TZ");
+	}
+	tzset();
+	return ret;
+}
diff --git a/c/lib/mlrdatetime.h b/c/lib/mlrdatetime.h
new file mode 100644
index 000000000..85e6c86f4
--- /dev/null
+++ b/c/lib/mlrdatetime.h
@@ -0,0 +1,14 @@
+#ifndef MLRDATETIME_H
+#define MLRDATETIME_H
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+double get_systime();
+
+// portable timegm replacement
+time_t mlr_timegm (struct tm *ptm);
+
+#endif // MLRDATETIME_H