friend has horrible communication and time management

i’m friends with this one person and i really enjoy their company but they are awful with communication and time. we are (or were?) supposed to hang out today, last they told me they would have to confirm today if it was still possible i said okay but worries. it’s currently 5 pm here and they just replied to me saying they were at work but nothing about if we are still meeting up. they do this.every.single.time. every time we are supposed to meet up i don’t hear from them the entire day until right before the hangout, and then a lot of the time its them asking to push the time back. it’s honestly so frustrating and i don’t know how to tell them without seeming rude. because it feels like they expect me to my entire day on pause waiting for them to respond to me.