ping and interval option

why in console mode ping command not support interval parametr other than integer?
in winbox version of ping it is timeout option which I set for example to 100ms

in MT 2.8.x it worked
in MT 2.9.x not

Lorzelek
ping x.x.x.x interval=5
works for me in 2.9.20 version,

all commands that come with ‘ping’,
ping x.x.x.x
arp-interface count do-not-fragment interval size src-address ttl

fine, interval=5 works, but interval=0.05 not
in MT 2.8.x it worked