+/**
+ * Gets the current day number.
+ *
+ * Gets the current day number used to generate the most recent DTK.
+ *
+ * The day number is calculated as:
+ * (Number of Seconds since Epoch) / (60 * 60 * 24)
+ *
+ * Which can be caluclated from the current epoch using the
+ * epoch_to_day_number() function.
+ *
+ * @param data The context object to work with.
+ * @return The day number most recently used to generate the DTK.
+ */
+uint32_t contrac_get_day_number(Contrac * data) {
+ return dtk_get_day_number(data->dtk);
+}
+
+/**
+ * Gets the current time interval number.
+ *
+ * Gets the current time interval number used to generate the most recent RPI.
+ *
+ * The time interval number is calculated as:
+ * (Seconds Since Start of DayNumber) / (60 * 10)
+ *
+ * and must fall in the interval [0, 143].
+ *
+ * It can be caluclated from the current epoch using the
+ * epoch_to_time_interval_number() function.
+ *
+ * @param data The context object to work with.
+ * @return The time interval number most recently used to generate the RPI.
+ */
+uint8_t contrac_get_time_interval_number(Contrac * data) {
+ return rpi_get_time_interval_number(data->rpi);
+}
+
+/**
+ * Sets the Tracing Key for the device in binary format.
+ *
+ * When first configuring a system, the Tracing Key must be generated
+ * randomly, e.g. using contrac_generate_tracing_key().
+ *
+ * However, on future runs it's important that the Tracing Key stays the same.
+ * In this case the key can be restored using this function.
+ *
+ * The tracing_key buffer passed in must contain exactly TK_SIZE (32) bytes of
+ * data.It doen't have to be null terminated.
+ *
+ * @param data The context object to work with.
+ * @param tracing_key The Tracing Key to set in binary format.
+ */