diff --git a/include/Clock.h b/include/Clock.h
index 234800b..87ff289 100644
--- a/include/Clock.h
+++ b/include/Clock.h
@@ -11,14 +11,12 @@
 #include <chrono>
 
 void clock_setup(void);
+SNTPError clock_sync(NetworkInterface &net);
 
 std::chrono::microseconds clock_now(void);
 
-SNTPError clock_sync(NetworkInterface &net);
-
 const char *clock_timestring(std::chrono::microseconds, const char *format);
 const char *clock_iso8601string(std::chrono::microseconds);
-
 const char *clock_iso8601string_now(void);
 
 #endif
diff --git a/src/Clock.cpp b/src/Clock.cpp
index f1e921c..acc181f 100644
--- a/src/Clock.cpp
+++ b/src/Clock.cpp
@@ -8,16 +8,12 @@
 
 using namespace std::chrono;
 
+// Initializes the clock, run once at boot
 void clock_setup(void) {
 	// mbed reads the RTC at boot, do nothing for now
 }
 
-microseconds clock_now(void) {
-	time_t now_seconds = time(NULL);
-	microseconds microsecs = seconds(now_seconds);
-	return microsecs;
-}
-
+// Syncs the clock using SNTP, run any time
 SNTPError clock_sync(NetworkInterface &net) {
 	struct timeval time;
 	SNTPError err;
@@ -29,6 +25,18 @@
 	return SNTPSuccess;
 }
 
+// Gets the current clock time in microseconds since 1970
+microseconds clock_now(void) {
+	time_t now_seconds = time(NULL);
+	microseconds microsecs = seconds(now_seconds);
+	return microsecs;
+}
+
+// Formats a time in microseconds using strftime
+// Returned value is a buffer containing the formatted string
+// or "(time overflow)"
+// Calling this function overwrites the previous buffer contents
+// so if you want to preserve it please copy the string
 const char *clock_timestring(microseconds time, const char *format) {
 	time_t time_seconds = ceil<seconds>(time).count();
 	struct tm *local_time = localtime(&time_seconds);
@@ -46,6 +54,11 @@
 	}
 }
 
+// Formats a time in microseconds according to ISO 8601
+// Returned value is a buffer containing the formatted string
+// or "(iso8601 overflow)"
+// Calling this function overwrites the previous buffer contents
+// so if you want to preserve it please copy the string
 const char *clock_iso8601string(microseconds time) {
 	const char *timestring = clock_timestring(time, "%Y-%m-%dT%H:%M:%S");
 	long only_microseconds = time.count() % 1000000;
@@ -64,7 +77,9 @@
 	}
 }
 
+// Formats the current time in microseconds according to ISO 8601
+// This is a quick wrapper for clock_iso8601string using the current
+// clock time. Read its documentation for full usage details
 const char *clock_iso8601string_now(void) {
-	microseconds now = clock_now();
 	return clock_iso8601string(clock_now());
 }