(Fig. \[fig:timeResEnvelopesAndFilter\](a)). CMS software was subsequently adjusted by smearing the times of simulated HCAL energy deposits so that simulated data of the test beam configuration exhibited the same energy-dependent time resolution (Fig. \[fig:timeResEnvelopesAndFilter\](b)).

![(a) Timing resolution as a function of energy measured during test beam runs in 2006, showing the consistency of time reconstruction for particles that begin showering in the ECAL (lines) and those that do not (areas). (b) Timing resolution as a function of energy of reconstructed deposits generated from CMS simulations. The lines marked “Time Filter” indicate the boundaries of a timing window discussed later and used to accept or reject deposits for distinguishing signal from background.[]{data-label="fig:timeResEnvelopesAndFilter"}](fig/tb06TimeResEnvelope "fig:"){width="48.00000%"} ![(a) Timing resolution as a function of energy measured during test beam runs in 2006, showing the consistency of time reconstruction for particles that begin showering in the ECAL (lines) and those that do not (areas). (b) Timing resolution as a function of energy of reconstructed deposits generated from CMS simulations. The lines marked “Time Filter” indicate the boundaries of a timing window discussed later and used to accept or reject deposits for distinguishing signal from background.[]{data-label="fig:timeResEnvelopesAndFilter"}](fig/MCtimeResEnvelopeAndFilter "fig:"){width="48.00000%"}

LHC beam data {#sec:splash}
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Data from LHC beam commissioning were 