Recognizing date ranges in Calc

[access]

Since the start of 2020, I’ve been tracking weekly traffic to a website in Calc and using the data to create a chart. When I originally set it up, I entered the date range for the week (i.e., 0104-0111 for Jan. 4-11) in one of the columns and set it on the chart’s X-axis (see screenshot below). The problem I’ve run into is that, starting in January 2021, it got confusing because the year is not displayed. Is there an easy way to go back and add the year in, preferably by having Calc recognize that the cells include a range of dates?

TIA

[JohnSUN]

Welcome! Easy way? Yes. Just use Ctrl+H. First select all cells for 2020 and replace ^. with 20& (regexp ON, Current selection only ON). Repeat with Find - and Replace -20. Then repeat for 2021

[access]

I very much appreciate your response. Unfortunately, I’m not so proficient in regular expressions. When I find ^. and replace with 20& and then find - and replace with -20 I end up with “200106-200112.” Is there a way to simply insert the year before the date, as in: “2020 0106-0112”?

[access]

I think I found a solution. I changed the week from a date range to week numbers — i.e., 2020-01, for the first week of 2020 and formatted the cell as YYYY-WW.