diff --git a/src/util/time.hpp b/src/util/time.hpp
index cf497af..0d1250d 100644
--- a/src/util/time.hpp
+++ b/src/util/time.hpp
@@ -303,7 +303,7 @@
  * \param format desired output format (default: `%Y-%m-%d %H:%M:%S`)
  * \param locale desired locale (default: "C" locale)
  *
- * \sa http://www.boost.org/doc/libs/1_54_0/doc/html/date_time/date_time_io.html#date_time.format_flags
+ * \sa https://www.boost.org/doc/libs/1_58_0/doc/html/date_time/date_time_io.html#date_time.format_flags
  *     describes possible formatting flags
  **/
 std::string
@@ -321,7 +321,7 @@
  * \param format input output format (default: `%Y-%m-%d %H:%M:%S`)
  * \param locale input locale (default: "C" locale)
  *
- * \sa http://www.boost.org/doc/libs/1_54_0/doc/html/date_time/date_time_io.html#date_time.format_flags
+ * \sa https://www.boost.org/doc/libs/1_58_0/doc/html/date_time/date_time_io.html#date_time.format_flags
  *     describes possible formatting flags
  */
 system_clock::TimePoint