Present Perfect 2 – When time period is continuing

I have played tennis today.

Present Perfect when the time period is continuing

We use the Present Perfect when the time period is continuing.
Again there is a connection between the past and the present.

Example
I have played tennis today.
Today started at midnight and is continuing.

Today started at midnight and is continuing.

So even though the action has finished the time period is continuing, so there is a connection between the past and the present. We therefore use the present perfect.
Example
I have been on holiday this year.

I have been on holiday this year.

This year started on 1st January, today is 16th May for example, so it started in the past, is continuing and so we use the present perfect.