Prohexadione calcium is a plant growth regulator used in peanut (Arachis hypogaea L.) to manage vegetative growth to improve efficiency of digging pods and inverting vines. In some cases, this plant growth regulator can increase peanut yield compared with non-treated peanut. The influence of planting date and digging date on peanut response to prohexadione calcium has not been determined with cultivars that are currently grown commercially. To address this issues, one experiment was conducted in North Carolina over two years to determine if planting date and digging date affected peanut response to prohexadione calcium applied when 50% of lateral branches from adjacent rows touched, followed by a second application 14 to 20 days later. The experiment included 2 levels of prohexadione calcium (0 and 140 g ai/ha), three levels of planting date (early, mid-, and late-May), and four levels of digging date (early and late-September and early and mid-October). In a second experiment conducted over six years, these prohexadione calcium treatments were compared following a single planting date in early to mid-May each year, with six digging dates occurring approximately 115, 122, 129, 136, 143, and 150 days after planting. Peanut yield was affected by the interaction of planting date and digging date independent of prohexadione calcium treatment. Peanut response to prohexadione calcium was affected by year, with peanut yield lower when prohexadione calcium was applied compared with non-treated peanut in one year; yield was similar in the other year of the experiment. In the second experiment with six digging dates, prohexadione calcium did not affect peanut yield regardless of year or digging date. A cubic response was observed for peanut yield vs. digging date when data were pooled over years and prohexadione calcium rates. Results from these experiments suggest that peanut yield will not be affected by prohexadione calcium, irrespective of planting date or digging date. It is important to note that these experiments were conducted using accepted small-plot techniques for peanut (e.g., plot sizes of 1.8 m by 9 m). Additional research is needed to support or refute these results using larger plots in farmer’s fields.