Four-day school week (4DSW) schedules are growing rapidly across the U.S., with school districts citing perceived benefits to teacher recruitment and retention and student attendance as motivations for adopting the schedule. This study uses panel data from Colorado, one of the states with the highest prevalence of 4DSWs, to investigate the impacts of the 4DSWs on the percentage of teachers with shortage credentials, teacher attrition rates, and student attendance rates. Utilizing a synthetic control difference-in-differences research design, we find 4DSWs have small negative or statistically insignificant effects on teacher recruitment and retention outcomes and find little variation in these effects by school rurality. Examining student attendance outcomes, we estimate a meaningfully small 0.76 percentage point reduction in attendance rates associated with adopting a 4DSW in non-rural schools (equivalent to 46% of these schools' typical yearly fluctuations in ADA) but do not detect an effect in small rural or non-rural schools. These findings suggest that these purported benefits of 4DSWs are not realized in Colorado, warranting concern about the continued use and expansion of this schedule given prior evidence of its negative average impacts on student achievement.