Distribution of the SEP events with respect to timing differences (in minutes) between the > 100 MeV proton events release times determined with SOHO/ERNE SEP onset and the associated solar signatures onsets. Two travel-time assumptions are considered: short (light colours) and long (dark colours) path lengths, respectively, 1 and 2.5 AU. Solar signatures are shifted to the solar time according to the light travel time, and are, from left to right: CME first appearance in SOHO/LASCO coronographs (blue), soft X-ray onset time (red), hard X-ray onset time (yellow), type II radio burst onset time (purple), type III radio burst onset time (green), type IV radio burst onset time (cyan), gamma ray burst onset time (pink). In each boxplot, the middle line indicates the median of the distribution whereas the top of bottom edges of a box are the upper and lower quartiles, respectively. Outliers are values that are more than 1.5 times the distance between the top and bottom edges. The number of events considered in each boxplot is indicated in the x axis.