How to read Minecraft server player count history?

Current player count is one metric. To understand peak hours, look at a history chart with time range, sampling, and last metered time.

Step by step

Open the server in MCAPI and select the appropriate time period if there is saved history. Compare multiple days to separate temporary spikes from regular peaks.
Reading time periods with no samples as zero players. The server may not have responded or measurements were not taken.
If you're examining the impact of an event, note the start and end times on the chart. First compare with similar days and times.
Verify the current state, the last point of the chart, and the timestamp together. If the proxy publishes the total network count, do not use that as the single game mode count.

The chart tracks the value reported by the server. It does not verify player identities or each connection individually.