I know this is probably in the wrong forum, so move it if you want moderators. Anyway,
What is the shortest time control FIDE allows AND will rate the games for a standard (slow chess) rating? Please give the answer in minutes/seconds, and I don’t care about “interval” (or whatever they call the extra time you get for making a move). Thanks!
Answer: depends on the player field. But in general, I usually see 90 minutes + 30 second increments.
Please note that G/90 with a 30 second increment would be equivalent to 120 minutes per player over 60 moves. Just as a time control of G/105 with a 15 second increment would be equivalent to 120 minutes per player over 60 moves. If someone can find it please point out where the latest FIDE arbiter’s manual sets a minimum limit on the length of the increment. Thank you.
Larry S. Cohen
For all players in a section? 120 minutes, no seconds.
Alex Relyea
Under “Glossary of terms in the Laws of Chess” (page 52):
You should probably get used to increment, regardless of your various complaints. It is here to stay.
Based on the above, I assumed Mr. Campbell does not care for delay either.
Alex Relyea
I’d use a sandglass but the Director says I should use at least a Jerger or BHB. Oh, how I long for the days where I can set up the board with the sun at my back and smoke a cigar in my opponent’s face!
How 'bout sundials – to complete your move you take the cover off your opponent’s sundial and put it on yours? :mrgreen:
Or a sand timer 
. Page 10-11 of the January 2017 Chess Life was particularly apropos!
No, no, no, no, no.
You need something that can work just fine with either a stationary light source or with multiple light sources that pretty much wipe out any shadows.
A biological method might work. Take a two foot long block with a two inch deep groove and place a snail at the one foot point facing White. Whenever you move turn the snail around. Once the snail reaches your side you lose on time. 
Actually, I believe on of the first clocks worked that way. It was a metal ball in a tube of oil. The tube was tipped back and forth between the players, and if the ball got to the end, game over.
The Chronos simulates this in its “hourglass” mode. When one clock face is counting down, the other is counting up. So you should start the game with a small amount of time, say, 5 minutes.
Bill Smythe