Progression of optical observations over the full KiDS survey, for pointings within the final 1347 deg² footprint. The total number of DR5 pointings is shown as the dashed grey line. The figure demonstrates the slow initial progress made by the survey, whereby only ~5% of planned r-band observations were completed in the initial 18 months of data-taking, prompting changes in the queuing of (in particular) the dark-time observations. Conversely, at the end of the survey, the complete second-pass of i-band observations (designated i₂) was completed in roughly the same time span.