Timing is difficult to determine in Horary I agree, however if the significators are clear and aspected it is much easier. Sometimes it boils down to the moons placement either angular succeedent and cadent houses as to whether its a long way off, near or very close.
Its the mixture of significators in different elements that creates headaches, Fixed is unchanging, mutable is moveable and Cardinal is quick smart. One must make sound judgements on these and convert to time frames.
I agree that timing and "when will questions" are sometimes easier and then other times difficult.
Of course "when will" questions must also show that the 'thing' will actually happen otherwise there is no point.
kingsley