diff --git a/ds3231/main.cpp b/ds3231/main.cpp
index 4c176b9..c2c2110 100644
--- a/ds3231/main.cpp
+++ b/ds3231/main.cpp
@@ -1,5 +1,7 @@
 #include "clock.hpp"
 
+#include <stdlib.h>
+
 #include "ds3231/ds3231.hpp"
 #include "uart/uart.hpp"
 
@@ -62,28 +64,113 @@ static inline void printLocalTime(const rtc::DateTime &dateTime)
 	serial << dateTime << (dst ? F(" +2") : F(" +1")) << F("\r\n");
 }
 
+static inline bool operator==(const rtc::DateTime &lhs, const rtc::DateTime &rhs)
+{
+	if (lhs.second != rhs.second)
+		return false;
+	if (lhs.minute != rhs.minute)
+		return false;
+	if (lhs.hour != rhs.hour)
+		return false;
+	if (lhs.day != rhs.day)
+		return false;
+	if (lhs.month != rhs.month)
+		return false;
+	if (lhs.year != rhs.year)
+		return false;
+	return true;
+}
+
+static inline bool operator!=(const rtc::DateTime &lhs, const rtc::DateTime &rhs)
+{
+	return !(lhs == rhs);
+}
+
+static inline size_t receiveLine(char *buffer, const size_t maxLength)
+{
+	uart_t serial;
+	size_t received = 0;
+
+	while (received < maxLength) {
+		if (serial.rxByte(*reinterpret_cast<uint8_t *>(&buffer[received]))) {
+			++received;
+			if (buffer[received - 1] == '\r' || buffer[received - 1] == '\n')
+				break;
+		}
+	}
+
+	return received;
+}
+
+static inline rtc::DateTime receiveTime()
+{
+	uart_t serial;
+
+	rtc::DateTime dateTime;
+	constexpr auto BUF_LEN = 8;
+	char receiveBuffer[BUF_LEN];
+
+	serial << F("Enter year: ");
+	auto receivedLen = receiveLine(receiveBuffer, BUF_LEN);
+	receiveBuffer[receivedLen] = '\0';
+	dateTime.year = atoi(receiveBuffer);
+
+	serial << F("\r\nEnter month: ");
+	receivedLen = receiveLine(receiveBuffer, BUF_LEN);
+	receiveBuffer[receivedLen] = '\0';
+	dateTime.month = atoi(receiveBuffer);
+
+	serial << F("\r\nEnter date: ");
+	receivedLen = receiveLine(receiveBuffer, BUF_LEN);
+	receiveBuffer[receivedLen] = '\0';
+	dateTime.day = atoi(receiveBuffer);
+
+	serial << F("\r\nEnter hour: ");
+	receivedLen = receiveLine(receiveBuffer, BUF_LEN);
+	receiveBuffer[receivedLen] = '\0';
+	dateTime.hour = atoi(receiveBuffer);
+
+	serial << F("\r\nEnter minute: ");
+	receivedLen = receiveLine(receiveBuffer, BUF_LEN);
+	receiveBuffer[receivedLen] = '\0';
+	dateTime.minute = atoi(receiveBuffer);
+
+	serial << F("\r\nEnter second: ");
+	receivedLen = receiveLine(receiveBuffer, BUF_LEN);
+	receiveBuffer[receivedLen] = '\0';
+	dateTime.second = atoi(receiveBuffer);
+	serial << F("\r\n");
+
+	return dateTime;
+}
+
 int main()
 {
-	uart_t cSerial;
+	uart_t serial;
 	rtc::DS3231<i2c::I2c<i2c::Hardware<100'000>>, false> ds3231;
 
 	ds3231.init();
-	cSerial.init();
+	serial.init();
 
-	rtc::DateTime date;
-	date.year = 2020;
-	date.month = 01;
-	date.day = 01;
-	date.hour = 19;
-	date.minute = 18;
-	date.second = 50;
-
-	ds3231.setDateTime(date);
+	auto oldDate = ds3231.getDateTime();
 
 	while (true) {
 		const auto date = ds3231.getDateTime();
-		printLocalTime(date);
-		_delay_ms(1000);
+
+		if (oldDate != date) {
+			oldDate = date;
+			printLocalTime(date);
+		}
+
+		uint8_t receivedByte;
+
+		if (serial.rxByte(receivedByte)) {
+			if (receivedByte == 's') {
+				const auto newDate = receiveTime();
+				ds3231.setDateTime(newDate);
+			} else
+				serial << F("Invalid input: ") << static_cast<char>(receivedByte) << F("\r\n");
+		}
 	}
 
 	return 0;