The purpose of the present study was to evaluate the effect of time (season, surgical starting time in the daytime, preoperative waiting time) on patients with gastric cancer. Methods: A retrospective collection of medical records of patients who underwent gastrectomy at a single clinical center from January 2013 to December 2018 was performed. Medical records were collected, and short-term outcomes and long-term survival were analyzed by different time groups. Results: A total of 586 patients were included in this study. In terms of surgical starting time, the midday group had a shorter operation time (p=0.017) but more complications (p=0.048) than the non-midday group. No significant difference was found based on the season of gastrectomy. The long preoperative waiting group had a shorter postoperative hospital stay than the short waiting group (p=0.026). No significant difference was found between the short-waiting group and long-waiting group in overall survival for all clinical stages. Age (p=0.040, HR=1.017, 95% CI=1.001-1.033), BMI (p<0.001, HR=0.879, 95% CI=0.844-0.953) and clinical stage (p<0.001, HR=2.053, 95% CI=1.619-2.603) were independent prognostic factors predicting overall survival; however, season of gastrectomy, surgical starting time and preoperative waiting time were not identified as independent prognostic factors. Conclusion: Surgical starting time at the midday could cause more complications, and surgeons should be careful when the surgical starting time is midday.