いつからか

expression, adverb

since some time or another; since who-knows-when

Expresses that something has been the case for an indefinite period starting at an unknown point in the past. Often used when the speaker cannot pinpoint when a state or habit began.

• いつからか、彼かれは毎まい朝あさジョギングをするようになった。

  Since some time or another, he has taken up jogging every morning.

• この町まちにはいつからか猫ねこが増ふえた気きがする。

  I feel like the number of cats in this town has increased since who-knows-when.