This research was carried out in dry conditions in the trial land of Igdir University Faculty of Agriculture in 2019 and 2020. Effects on crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), dry matter digestibility (DMD), dry matter intake (DMI), digestible energy (DE), metabolizable energy (ME) and relative feed value (RFV) of sowing (mid-March, late-March, early-April and mid-April) and harvesting times (end of vegetative period, beginning of flowering and full flowering period) of mountain spinach (Atriplex nitens) were determined. The experiment was set up in randomized blocks according to the split plot design with 3 replications. It was determined that the crude protein obtained in the second year of the study was higher than the first year. Other examined hay quality characteristics did not change over the years. Sowing times had significant effects on all the nutrients studied. Delaying the sowing times resulted in decreases in NDF and ADF ratios, and increases in CP, DMD, DMI, DE, ME and RFV. While the NDF and ADF ratios increased with the delay of the harvest periods, there were decreases in the CP, DMD, DMI, DE, ME and RFV amounts. According to year, sowing and harvesting periods, CP ratios between 5.94% and 13.86%, NDF ratios 50.29% an 64.33%, ADF ratios 29.48% and 41.01%, DMD ratios 56.96% and 65.93%, DMI ratios 1.86% and 2.39%, DE amount 2.71 and 3.09 Mcal kg-1, ME amount 2.22 and 2.54 Mcal kg-1 and RFV value 82.40 and 121.97 was found. According to the results of the study, it was determined that in order to obtain high quality herbage from mountain spinach in dry conditions, it should be sown in mid-March, which is the first sowing time, and harvested at the end of the vegetative period.