Top panel: LC of GRB 211211A observed by Swift/BAT in the 15−150 keV passband as an illustrative example. The bin time is 4 ms. The identified peaks are highlighted with red circles. The solid orange line shows the probability density function, Ψ(t) (Sect. 3.1), with arbitrary normalisation, assumed to generate fake peaks, and was obtained from smoothing the original LC with a boxcar window of 13.5 s to account for the non-stationary nature of GRB profiles (see Sect. 3.1). Small bottom panels: Three different examples (orange circles) of random sequences of peak times, ζ^(k), generated using Ψ(t) shown in the top panel; the red circles show the real peak times, also shown in the top panel.