[janci]

Not DB2, but the meaning is the same.

In a time-series (or event) table you have one date - when the data point is valid (event occurred).

In a temporal table you have two dates - interval when the data is valid.

In a bitemporal table you have two intervals. First describes when the data is valid in real world, the second when does the system know about the real-world state.

I.e. if company changed address on 2022-05-01 but the system will not get that information until three day later (2022-05-03) you have two validity intervals.

Then you may ask - what was the company address on 2022-05-02? And what did the system think the address was on 2022-05-02? You will get two different answers. This is important if you need e.g. to make a correction to previously issued invoice. You need to know what data was used for original invoice and what data should have been used.