If you can not do a toNumber() can you do a
<div class="d-block" dmx-text="serverconnect1.data.repeat1[0].eventstart.toDate().formatDate2('d')"></div>
OR
<div class="d-block" dmx-text="serverconnect1.data.repeat1[0].eventstart.toTimestamp().formatDate2('d')"></div>
to change the string first Teo?
Just asking for my own learning too.
Edit: Nevermind I saw your answer, without App Connect then nothing will work.