diff --git a/swe-glib/src/gswe-moment.c b/swe-glib/src/gswe-moment.c
index 1b83a2a..91d8bdf 100644
--- a/swe-glib/src/gswe-moment.c
+++ b/swe-glib/src/gswe-moment.c
@@ -1,9 +1,12 @@
 #include "swe-glib.h"
 #include "gswe-types.h"
 #include "gswe-moment.h"
+#include "swe-glib-private.h"
 
 #include "../../swe/src/swephexp.h"
 
+#define SYNODIC 29.53058867
+
 #define GSWE_MOMENT_GET_PRIVATE(obj) (G_TYPE_INSTANCE_GET_PRIVATE((obj), GSWE_TYPE_MOMENT, GsweMomentPrivate))
 
 /**
@@ -27,6 +30,8 @@ struct _GsweMomentPrivate {
     guint points_revision;
     GHashTable *element_points;
     GHashTable *quality_points;
+    guint moon_phase_revision;
+    GsweMoonPhaseData moon_phase;
 };
 
 enum {
@@ -94,6 +99,7 @@ gswe_moment_init(GsweMoment *moment)
     moment->priv->quality_points = g_hash_table_new_full(g_direct_hash, g_direct_equal, NULL, NULL);
     moment->priv->house_revision = 0;
     moment->priv->points_revision = 0;
+    moment->priv->moon_phase_revision = 0;
     moment->priv->revision = 1;
 }
 
@@ -527,3 +533,51 @@ gswe_moment_get_quality_points(GsweMoment *moment, GsweQuality quality)
     return point;
 }
 
+GsweMoonPhaseData *
+gswe_moment_get_moon_phase(GsweMoment *moment)
+{
+    gdouble difference,
+            phase_percent;
+
+    if (moment->priv->moon_phase_revision == moment->priv->revision) {
+        return &(moment->priv->moon_phase);
+    }
+
+    difference = (gswe_timestamp_get_julian_day(moment->priv->timestamp) - gswe_timestamp_get_julian_day(gswe_full_moon_base_date));
+    phase_percent = fmod((difference * 100) / SYNODIC, 100);
+
+    if (phase_percent < 0) {
+        phase_percent += 100.0;
+    }
+
+    if ((phase_percent < 0) || (phase_percent > 100)) {
+        g_error("Error during Moon phase calculation!");
+    }
+
+    moment->priv->moon_phase.illumination = (50.0 - fabs(phase_percent - 50.0)) * 2;
+
+    if (phase_percent == 0) {
+        moment->priv->moon_phase.phase = GSWE_MOON_PHASE_NEW;
+    } else if (phase_percent < 25) {
+        moment->priv->moon_phase.phase = GSWE_MOON_PHASE_WAXING_CRESCENT;
+    } else if (phase_percent == 25) {
+        moment->priv->moon_phase.phase = GSWE_MOON_PHASE_WAXING_HALF;
+    } else if (phase_percent < 50) {
+        moment->priv->moon_phase.phase = GSWE_MOON_PHASE_WAXING_GIBBOUS;
+    } else if (phase_percent == 50) {
+        moment->priv->moon_phase.phase = GSWE_MOON_PHASE_FULL;
+    } else if (phase_percent < 75) {
+        moment->priv->moon_phase.phase = GSWE_MOON_PHASE_WANING_GIBBOUS;
+    } else if (phase_percent == 75) {
+        moment->priv->moon_phase.phase = GSWE_MOON_PHASE_WANING_HALF;
+    } else if (phase_percent < 100) {
+        moment->priv->moon_phase.phase = GSWE_MOON_PHASE_WANING_CRESCENT;
+    } else {
+        moment->priv->moon_phase.phase = GSWE_MOON_PHASE_DARK;
+    }
+
+    moment->priv->moon_phase_revision = moment->priv->revision;
+
+    return &(moment->priv->moon_phase);
+}
+
diff --git a/swe-glib/src/gswe-moment.h b/swe-glib/src/gswe-moment.h
index 97ae484..e17d043 100644
--- a/swe-glib/src/gswe-moment.h
+++ b/swe-glib/src/gswe-moment.h
@@ -60,6 +60,11 @@ typedef struct {
     guint revision;
 } GswePlanetData;
 
+typedef struct {
+    GsweMoonPhase phase;
+    gdouble illumination;
+} GsweMoonPhaseData;
+
 struct _GsweMoment {
     /* Parent instance structure */
     GObject parent_instance;
@@ -96,6 +101,7 @@ GList *gswe_moment_get_planets(GsweMoment *moment);
 GswePlanetData *gswe_moment_get_planet(GsweMoment *moment, GswePlanet planet);
 guint gswe_moment_get_element_points(GsweMoment *moment, GsweElement element);
 guint gswe_moment_get_quality_points(GsweMoment *moment, GsweQuality quality);
+GsweMoonPhaseData *gswe_moment_get_moon_phase(GsweMoment *moment);
 
 #endif /* __GSWE_MOMENT_H__ */
 
diff --git a/swe-glib/src/gswe-types.h b/swe-glib/src/gswe-types.h
index 1f58fec..149a999 100644
--- a/swe-glib/src/gswe-types.h
+++ b/swe-glib/src/gswe-types.h
@@ -81,6 +81,18 @@ typedef enum {
     GSWE_HOUSE_SISTEM_EQUAL
 } GsweHouseSystem;
 
+typedef enum {
+    GSWE_MOON_PHASE_NEW,
+    GSWE_MOON_PHASE_WAXING_CRESCENT,
+    GSWE_MOON_PHASE_WAXING_HALF,
+    GSWE_MOON_PHASE_WAXING_GIBBOUS,
+    GSWE_MOON_PHASE_FULL,
+    GSWE_MOON_PHASE_WANING_GIBBOUS,
+    GSWE_MOON_PHASE_WANING_HALF,
+    GSWE_MOON_PHASE_WANING_CRESCENT,
+    GSWE_MOON_PHASE_DARK
+} GsweMoonPhase;
+
 /**
  * GswePlanetInfo:
  * @planet:          the planet ID
diff --git a/swe-glib/src/swe-glib-private.h b/swe-glib/src/swe-glib-private.h
index 30ce07d..e794918 100644
--- a/swe-glib/src/swe-glib-private.h
+++ b/swe-glib/src/swe-glib-private.h
@@ -1,7 +1,10 @@
 #ifdef __SWE_GLIB_BUILDING__
 #ifndef __SWE_GLIB_PRIVATE_H__
 
+#include "gswe-timestamp.h"
+
 extern gchar *gswe_ephe_path;
+extern GsweTimestamp *gswe_full_moon_base_date;
 
 #endif /* __SWE_GLIB_PRIVATE_H__ */
 #else /* not defined __SWE_GLIB_BUILDING__ */
diff --git a/swe-glib/src/swe-glib.c b/swe-glib/src/swe-glib.c
index 320b3b2..0f15bfa 100644
--- a/swe-glib/src/swe-glib.c
+++ b/swe-glib/src/swe-glib.c
@@ -10,6 +10,7 @@ gchar *gswe_ephe_path = NULL;
 GHashTable *gswe_planet_info_table;
 GHashTable *gswe_sign_info_table;
 GHashTable *gswe_house_system_info_table;
+GsweTimestamp *gswe_full_moon_base_date;
 
 #define ADD_PLANET(ht, v, i, s, r, n, o, h, dom1, dom2, exi1, exi2, exa, fal) (v) = g_new0(GswePlanetInfo, 1); \
                                                                               (v)->planet = (i); \
@@ -122,6 +123,8 @@ gswe_init(gchar *sweph_path)
     ADD_HOUSE_SYSTEM(gswe_house_system_info_table, house_system_info, GSWE_HOUSE_SYSTEM_KOCH,     'K', _("Koch"));
     ADD_HOUSE_SYSTEM(gswe_house_system_info_table, house_system_info, GSWE_HOUSE_SISTEM_EQUAL,    'E', _("Equal"));
 
+    gswe_full_moon_base_date = gswe_timestamp_new_from_gregorian_full(2005, 5, 8, 3, 48, 0, 0, 0.0);
+
     gswe_ephe_path = g_strdup(sweph_path);
     swe_set_ephe_path(sweph_path);
     gswe_initialized = TRUE;