In the version of this Article originally published, the authors mistakenly used the same images for the Fig. 2d Per-/- upper Merge, DAPI and p-RPA2 (Ser33), and Fig. 3e upper 2 months, WT Per2 DAPI and Merge panels. The correct images from these experiments, and their correctly sized scale bars, are shown below. In addition, the full dataset of representative images for Figs 2d and 3e, and the numerical source data of the corresponding quantifications of Figs 2c and 3f, have been uploaded to Figshare ( https://doi.org/10.6084/m9.figshare.c.4353791.v1 ). In addition, the Methods section did not provide sufficient detail on how immunoblot experiments were conducted. Western blots were repeated three times using the antibodies stated in the Methods. PER2 blots were obtained using the PER2 antibody (Millipore, AB2202); except in the PER2 blots in the Repeat 1 experiments corresponding to Fig. 3g and 3k, where the PER2 antibody from BD Transduction (611138) was used. Repeats 1 and 2 were imaged using ECL and LI-COR methods, and Repeat 3 only used the LI-COR system. The images presented in the paper were from Repeat 3 and were stored electronically and as printouts, however the electronic versions were cropped as depicted in Supplementary Fig. 6. Repeat 1 images were stored electronically and Repeat 2 images only as printouts. In addition - with the exception of Figs 2g (ATM), 3g (PER2, Repeat 1A), 3k (PER2, PUMA, p21, BAX, BCL2) and Supplementary Fig. 1a of Repeat 1, in which actin immunoblots were loading controls processed from the same membranes used to detect the target proteins - in all other cases the actin blots were sample processing controls that were run in parallel using the same lysates and loading concentrations that were used for the detection of the target proteins. The electronic images from Repeat 1 and the printout images of Repeats 2 and 3 have been uploaded to Figshare ( https://doi.org/10.6084/m9.figshare.c.4353791.v1 ). Finally, there is an error in the protein size label of the p-CHK1 blot of Fig. 2f and the corresponding blot in Supplementary Fig. 6, which should read '55KD' instead of '50KD'.