For one cow, it's usually 11 to 12 months in between each calving. For a cow-calf operation with defined breeding and calving seasons, it's always 12 months in between the start of one season to the start of the next.
The age at first calving for this breed should be 24 months of age.
Two to three months post-partum.
Birthing, or calving.
The anestrous period for a cow or heifer after calving is 45 to 60 days, but can range between 25 to 80+ days.
Including the start and end months in the calculation, there are 7 months between the two months.
between 12½ months & 13 months
9 months
Four months are between December and April.
A cow that is very close to calving or which calving is imminent.
Calving or parturition.
Negative three to four months, assuming the cow gets bred two months after calving and the calf is weaned at six months of age. Seriously, a cow is already bred and into her second trimester when her calf is weaned. Cows are not like human females where they can only get pregnant again at least a year or 8 to 12 months post-partum.
Once every 11 to 12 months, accounting for the period of rest a cow gets after being bred (which will last from 2 to 3 months), and the gestation period for that cow after she has conceived.