xml structure personal organizer

i'm doing personal organizer training purposes, i've never worked xml i'm certain fortitude best. here's simple structure xml record i came with:

<calendar>
    <year value="2008">
        <month value="october">
            <day value="16">
                <activity name="mike's birthday" time="21:00" address="mike's apartment" urgency="10">
                     activity description.
                </activity>
            </day>
        </month>
    </year>
</calendar>

the duress charge should scale 1 10.

i discerning hunt google couldn't good example. maybe that's best solution, i'd know the adequate. i'm doing concentration php any relevance.