1 year (leap) = 0.143249 septennial; 1 septennial = 6.980874 year (leap)
h ↔ d
h ↔ min
h ↔ s
min ↔ s
s ↔ ms
ms ↔ us
Time +/- Hrs & mins
Date add Days
Date subtract Days
12hrs ↔ 24hrs
hr ↔ hr & min
min ↔ min & sec
hr ↔ day & hr
min ↔ hr & min
sec ↔ min & sec