Based on real-time trade data from the Swiss franc overnight interbank repo market and SIX Interbank Clearing (SIC) - the Swiss real-time gross settlement (RTGS) system - we are able to gain valuable insights on the daytime value of money and its determinants: First, an implicit hourly interbank interest rate can be derived from the intraday term structure of the overnight rate. We thereby provide evidence that an implicit intraday money market exists. Second, we show that after the introduction of the foreign exchange settlement system CLS the value of intraday liquidity has increased during the hours of the CLS settlement cycle. Third, the turnover as well as the liquidity in SIC influence the intraday rate correspondingly. These facts provide evidence for the cost of immediacy. Features like RTGS, delivery-versus-payment and payment-versus-payment substitute credit risk with liquidity risk which in turn increases the value of intraday liquidity. The analysis is central bank policy relevant insofar as different designs of intraday liquidity facilities and different collateral policies result in different intraday term structures for the overnight money market.