[chuck-users] cast dur to time?

Dear list (and language designers in particular), this is legal; now + 2::second => time later; so, we know that time and duration are quite similar things (we already knew that ourselves but now we know ChucK agrees). However, this isn't legal; 2::second $ time => time later; I tried this, intending "later" to refer to the moment 2 seconds after the VM sprang to life. Are there good reasons not to allow the casting from time to dur and dur to time? Yours, Kas.