Systematic and scoping reviews typically require a year or more to complete.
The Cochrane Collaboration has reported that comprehensive literature searches for systematic reviews may require 3 to 8 months for completion.
Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA (editors). Cochrane Handbook for Systematic Reviews of Interventions version 6.2 (updated February 2021). Cochrane, 2021. Available from www.training.cochrane.org/handbook.
Borah, R., et al. (2017). Analysis of the time and workers needed to conduct systematic reviews of medical interventions using data from the PROSPERO registry. BMJ Open, 7(2), e012545.