For those of you who may ever need to interface to a DS1307 I2C real time clock (it would wourk for the 1306 SPI RTC as well) here's a useful class.

private class RTCTime
{
 private byte[] m_bytes = new byte[7];
 
 public RTCTime()
 {
 }
 public RTCTime(byte[] data)
 {
  m_bytes = data;
 }
 public RTCTime(DateTime dateTime)
 {
  this.Second = dateTime.Second;
  this.Minute = dateTime.Minute;
  this.Hour = dateTime.Hour;
  this.Day = dateTime.Day;
  this.Month = dateTime.Month;
  this.Year = dateTime.Year;
 }
 public static implicit operator byte[](RTCTime rtc)
 {
  return rtc.m_bytes;
 }
 public static implicit operator RTCTime(byte[] bytes)
 {
  return new RTCTime(bytes);
 }
 public static explicit operator DateTime(RTCTime rtc)
 {
  return new DateTime(rtc.Year, rtc.Month, rtc.Day, rtc.Hour, rtc.Minute, rtc.Second, 0);
 }
 public int Second
 {
  get { return BCD_TO_WORD(m_bytes[0]); }
  set { m_bytes[0] = WORD_TO_BCD(value); }
 }
 public int Minute
 {
  get { return BCD_TO_WORD(m_bytes[1]); }
  set { m_bytes[1] = WORD_TO_BCD(value); }
 }
 public int Hour
 {
  get { return BCD_TO_WORD(m_bytes[2]); }
  set { m_bytes[2] = WORD_TO_BCD(value); }
 }
 public int DayOfWeek
 {
  get { return BCD_TO_WORD(m_bytes[3]); }
  set { m_bytes[3] = WORD_TO_BCD(value); }
 }
 public int Day
 {
  get { return BCD_TO_WORD(m_bytes[4]); }
  set { m_bytes[4] = WORD_TO_BCD(value); }
 }
 public int Month
 {
  get { return BCD_TO_WORD(m_bytes[5]); }
  set { m_bytes[5] = WORD_TO_BCD(value); }
 }
 public int Year
 {
  get { return BCD_TO_WORD(m_bytes[6]); }
  set { m_bytes[6] = WORD_TO_BCD(value); }
 }
 public int Length
 {
  get { return m_bytes.Length; }
 }
 private int BCD_TO_WORD(byte x)
 {
  return (x & 0x0f) + ((x >> 4) * 10);
 }
 private byte WORD_TO_BCD(int x)
 {
  return (byte)((x % 10) + ((x / 10) * 0x10));
 }
}