Every country and their health system tries to report the number of covid-19 cases and related-deaths on a nearly daily basis. However, the actual system in each country works differently. In some countries, a person can have symptoms, they can order a test and that can take a few days. Once the test is submitted the results can also take some time. So in a way the current tally is a reflection of a past state.
This is kind of similar to all the light coming from stars that are light years away from the earth. What we are seeing is a snapshot of the past.
Its good to keep this in mind on how reporting systems work and what the actual data implies in the real world. If for example financial reporting systems in a company is so much lagging behind that the financial statements are lagging to the actual day to day business, it can lead to a discrepancy between price and value quite quickly.