DateTime

contract DateTime {
        /*
         *  Date and Time utilities for ethereum contracts
         *
         *  address: 0x1a6184cd4c5bea62b0116de7962ee7315b7bcbce
         */
        struct DateTime {
                uint16 year;
                uint8 month;
                uint8 day;
                uint8 hour;
                uint8 minute;
                uint8 second;
                uint8 weekday;
        }

        uint constant DAY_IN_SECONDS = 86400;
        uint constant YEAR_IN_SECONDS = 31536000;
        uint constant LEAP_YEAR_IN_SECONDS = 31622400;

        uint constant HOUR_IN_SECONDS = 3600;
        uint constant MINUTE_IN_SECONDS = 60;

        uint16 constant ORIGIN_YEAR = 1970;

        function isLeapYear(uint16 year) constant returns (bool) {
                if (year % 4 != 0) {
                        return false;
                }
                if (year % 100 != 0) {
                        return true;
                }
                if (year % 400 != 0) {
                        return false;
                }
                return true;
        }

        function parseTimestamp(uint timestamp) internal returns (DateTime dt) {
                uint secondsAccountedFor = 0;
                uint buf;
                uint8 i;

                dt.year = ORIGIN_YEAR;

                // Year
                while (true) {
                        if (isLeapYear(dt.year)) {
                                buf = LEAP_YEAR_IN_SECONDS;
                        }
                        else {
                                buf = YEAR_IN_SECONDS;
                        }

                        if (secondsAccountedFor + buf > timestamp) {
                                break;
                        }
                        dt.year += 1;
                        secondsAccountedFor += buf;
                }

                // Month
                uint8[12] monthDayCounts;
                monthDayCounts[0] = 31;
                if (isLeapYear(dt.year)) {
                        monthDayCounts[1] = 29;
                }
                else {
                        monthDayCounts[1] = 28;
                }
                monthDayCounts[2] = 31;
                monthDayCounts[3] = 30;
                monthDayCounts[4] = 31;
                monthDayCounts[5] = 30;
                monthDayCounts[6] = 31;
                monthDayCounts[7] = 31;
                monthDayCounts[8] = 30;
                monthDayCounts[9] = 31;
                monthDayCounts[10] = 30;
                monthDayCounts[11] = 31;

                uint secondsInMonth;
                for (i = 0; i < monthDayCounts.length; i++) {
                        secondsInMonth = DAY_IN_SECONDS * monthDayCounts[i];
                        if (secondsInMonth + secondsAccountedFor > timestamp) {
                                dt.month = i + 1;
                                break;
                        }
                        secondsAccountedFor += secondsInMonth;
                }

                // Day
                for (i = 0; i < monthDayCounts[dt.month - 1]; i++) {
                        if (DAY_IN_SECONDS + secondsAccountedFor > timestamp) {
                                dt.day = i + 1;
                                break;
                        }
                        secondsAccountedFor += DAY_IN_SECONDS;
                }

                // Hour
                for (i = 0; i < 24; i++) {
                        if (HOUR_IN_SECONDS + secondsAccountedFor > timestamp) {
                                dt.hour = i;
                                break;
                        }
                        secondsAccountedFor += HOUR_IN_SECONDS;
                }

                // Minute
                for (i = 0; i < 60; i++) {
                        if (MINUTE_IN_SECONDS + secondsAccountedFor > timestamp) {
                                dt.minute = i;
                                break;
                        }
                        secondsAccountedFor += MINUTE_IN_SECONDS;
                }

                if (timestamp - secondsAccountedFor > 60) {
                        __throw();
                }

                // Second
                dt.second = uint8(timestamp - secondsAccountedFor);

                // Day of week.
                buf = timestamp / DAY_IN_SECONDS;
                dt.weekday = uint8((buf + 3) % 7);
        }

        function getYear(uint timestamp) constant returns (uint16) {
                return parseTimestamp(timestamp).year;
        }

        function getMonth(uint timestamp) constant returns (uint16) {
                return parseTimestamp(timestamp).month;
        }

        function getDay(uint timestamp) constant returns (uint16) {
                return parseTimestamp(timestamp).day;
        }

        function getHour(uint timestamp) constant returns (uint16) {
                return parseTimestamp(timestamp).hour;
        }

        function getMinute(uint timestamp) constant returns (uint16) {
                return parseTimestamp(timestamp).minute;
        }

        function getSecond(uint timestamp) constant returns (uint16) {
                return parseTimestamp(timestamp).second;
        }

        function getWeekday(uint timestamp) constant returns (uint8) {
                return parseTimestamp(timestamp).weekday;
        }

        function toTimestamp(uint16 year, uint8 month, uint8 day) constant returns (uint timestamp) {
                return toTimestamp(year, month, day, 0, 0, 0);
        }

        function toTimestamp(uint16 year, uint8 month, uint8 day, uint8 hour) constant returns (uint timestamp) {
                return toTimestamp(year, month, day, hour, 0, 0);
        }

        function toTimestamp(uint16 year, uint8 month, uint8 day, uint8 hour, uint8 minute) constant returns (uint timestamp) {
                return toTimestamp(year, month, day, hour, minute, 0);
        }

        function toTimestamp(uint16 year, uint8 month, uint8 day, uint8 hour, uint8 minute, uint8 second) constant returns (uint timestamp) {
                uint16 i;

                // Year
                for (i = ORIGIN_YEAR; i < year; i++) {
                        if (isLeapYear(i)) {
                                timestamp += LEAP_YEAR_IN_SECONDS;
                        }
                        else {
                                timestamp += YEAR_IN_SECONDS;
                        }
                }

                // Month
                uint8[12] monthDayCounts;
                monthDayCounts[0] = 31;
                if (isLeapYear(year)) {
                        monthDayCounts[1] = 29;
                }
                else {
                        monthDayCounts[1] = 28;
                }
                monthDayCounts[2] = 31;
                monthDayCounts[3] = 30;
                monthDayCounts[4] = 31;
                monthDayCounts[5] = 30;
                monthDayCounts[6] = 31;
                monthDayCounts[7] = 31;
                monthDayCounts[8] = 30;
                monthDayCounts[9] = 31;
                monthDayCounts[10] = 30;
                monthDayCounts[11] = 31;

                for (i = 1; i < month; i++) {
                        timestamp += DAY_IN_SECONDS * monthDayCounts[i - 1];
                }

                // Day
                timestamp += DAY_IN_SECONDS * (day - 1);

                // Hour
                timestamp += HOUR_IN_SECONDS * (hour);

                // Minute
                timestamp += MINUTE_IN_SECONDS * (minute);

                // Second
                timestamp += second;

                return timestamp;
        }

        function __throw() {
                uint[] arst;
                arst[1];
        }
}