Description of data Validation data provided here was used to generate figures for 'OPETH: Open Source Solution for Real-time Peri-event Time Histogram Based on Open Ephys' by András Széll, Sergio Martínez-Bellver, Panna Hegedüs and Balázs Hangya, depositied on bioRxiv: https://www.biorxiv.org/content/10.1101/783688v1 The experimental data is provided in Cellbase format. CellBase software is a Matlab-based, open source data handling and analysis tool, and available at https://github.com/hangyabalazs/CellBase See CellBase documentation for details on variable structure. The Behaviour/ folder contains tetrode recordings in a behavioural recording sesssion: event.mat contains TTL event timestamps. TT1.mat, TT2.mat,... contains spike data from each tetrode. TT1_1.mat,... contains spike data after spike sorting in MClust (A.D.Redish). DBO07_190826a.mat contains raw behavioural data. TrialEvents.mat contains Trial events structure (see CellBase). StimEvents.mat contains Stimulus events structure (see CellBase). EVENTSPIKES and STIMSPIKES files contain pre-aligned spike times (see CellBase). The Tagging/ folders contain tetrode recordings in optogenetic tagging sesssions in the same format. --- oo --- Description of code lightpsth.m is included, which was used to calculated light-triggered PETH for unsorted tetrode data offline. All other code, including offline PETH tools for sorted data are part of MClust 3.5 (A.D Redish) or CellBase software packagages, available online.