• Largest meta-analysis of time-related elasticities; 704 observations from 102 studies. • Empirical examination of the neglected issue of the length of the long run. • Time elasticities found to depend upon many important policy relevant variables. • Meta-analysis results challenge some official elasticity recommendations. • Time-related elasticities can be forecast for range of situations. Far less attention has been paid in review studies to time-related elasticities than price elasticities, and this is partly because there is less evidence. Nonetheless, time elasticities are important parameters for transport planning, forecasting and appraisal. This paper builds upon Wardman (2012) , which then provided the most extensive account of demand elasticities to car, rail and bus time, rail and bus headway, and rail generalised journey time. It is based upon 741 elasticities drawn from 102 British studies published between 1977 and 2020, as opposed to the 427 elasticities from 69 studies published up to 2010 in the previous study. It recovered significant effects for attribute, mode, data used in estimation, distance, journey purpose, the measure of demand response and area type, all of which can be implemented in practical demand forecasting. It was unable to detect variations in elasticities over time, despite extensive testing, but casts doubts on whether elasticities drawn from discrete choice models represent long run effects and on the reliability of elasticities estimated to cross-sectional demand and transfer price data. Whilst we identify long run elasticities, of themselves these are limited if it is not known how long the long run is. Complementary insight is presented on the length of the long run, although this revealed quite significantly that the long run is critically dependent upon the periodicity of the time-series data used in estimation. The estimated meta-model provides credible demand elasticities for the variables covered. These implied elasticities are useful for benchmarking purposes and where no other evidence exists. We regard them to be transferable to similar situations outside of the British context to which they relate, particularly the methodological insights and the incremental elasticity effects. The implied elasticities are in some cases somewhat different to the previous study and also provide challenges to the elasticities recommended by the Department for Transport and the railway industry in Great Britain.