How to calculate the stem & branch of the Hour

• Take the daily stem and lookup the stem and branch of the first double hour
• If daily stem is S1 or S6;       1st double hourly stem = 1
  If daily stem is S2 or S7;      1st double hourly stem = 3
  If daily stem is S3 or S8;      1st double hourly stem = 5
  If daily stem is S4 or S9;      1st double hourly stem = 7
  If daily stem is S5 or S10;     1st double hourly stem = 9

• Double hourly stem = Add number of double hours to the 1st double hourly stem. (after S10 the stem cycle starts again with S1…)
• Double hourly branch = Add number of double hours to 1 (the 1st double hourly branch,  23:00-01:00) (after B12 the stem cycle starts again with B1…)