Technically speaking there is no “delay”
There is the “standard” 10-20 seconds BUT the problem is that this encoding and transmission delay is different for everyone watched based on the quality they selected (or slow internet they are on, or even mobile internet)
So I wouldn’t bother with a delay for what you are doing.
On a side note what API are you using, I’m unfamiliar with Spotify having a API last time I checked. (I push to last.fm and consume last.fm API instead)