[Web MIDI API] send() timestamp

Hi,   
I'm a bit confused… why does the API require a timestamp relative to some time (i.e., performance.now())? For example:  

output.send(data, performance.now() + time);  

It seems to me that it would be better to just let the second argument be a delay (as a high resolution timestamp):

//wait a few millis
output.send(data, millis);  


The problem is that timestamps in the past always resolve to 0 (i.e., play now!), so seems kinda pointless to rely on a timestamp.  What am I missing?  

--  
Marcos Caceres

Received on Friday, 14 December 2012 19:24:35 UTC