Hoping for fall – and cooler weather – to come soon.
Literally: one – day – three – autumn(s)
Alternately: A single day seems like three years. Each moment seems to drag on. Waiting impatiently.
Notes: The first half can be pronounced ichi.jitsu. The latter half can be written 千秋 (sen.shuu; “one thousand autumns”). The whole phrase can be followed by ～の思い (~no omoi; “the feeling of ~”).