Workfront calendars do not allow to rearrange items that have once been added, additionally you cannot organize calendars as well if you have couple.
This essentially means that if you want to rearrange something you need to delete an element and recreate it in another position. This is ridiculous in 2022.
if anyone feels the same, please consider upvoting these 2 ideas, one is mine, anothe 1 I found in innovation lab:
https://one.workfront.com/s/idea/0870z000000PSg0AAG/detail
https://one.workfront.com/s/idea/0874X000000oOk6QAE/detail
I would love to tag here Kyna Baker (community manager), but tagging doesn't work for me at the moment
cheers!