1 files changed, 3 insertions, 0 deletions
diff --git a/include/datetime/date-time.h b/include/datetime/date-time.h
index f861c2e..4be35f7 100644
--- a/include/datetime/date-time.h
+++ b/include/datetime/date-time.h
@@ -61,10 +61,13 @@ public:
     bool operator<=(const DateTime& that) const;
     bool operator!=(const DateTime& that) const;
     bool operator==(const DateTime& that) const;
+    int64_t operator- (const DateTime& that) const;
 
     static bool is_same_day(const DateTime& a, const DateTime& b);
     static bool is_same_minute(const DateTime& a, const DateTime& b);
 
+    bool is_set() const { return m_dt != nullptr; }
+
 private:
     std::shared_ptr<GDateTime> m_dt;
 };