I have no idea what happened here, but it may be that test are sometimes loaded a few days later.<p>For example here in Argentina he had a huge peak on October 1st 2020 <a href="https://ourworldindata.org/explorers/coronavirus-data-explorer?zoomToSelection=true&facet=none&pickerSort=asc&pickerMetric=location&hideControls=true&Metric=Confirmed+deaths&Interval=New+per+day&Relative+to+Population=true&Color+by+test+positivity=false&country=~ARG" rel="nofollow">https://ourworldindata.org/explorers/coronavirus-data-explor...</a> but it's not a real peak. Some death reports were misplaced and found later and loaded into the system that day (or the previous day, I'm not sure about the details).<p>Edit: Apparently the timestamp is the date of download. More details in <a href="https://news.ycombinator.com/item?id=29892505" rel="nofollow">https://news.ycombinator.com/item?id=29892505</a>