Mostly, on my phone's clock, it goes like 10:01, 13:13, 12:21. At first, I usually ignoring it and taking it as just a coincidence. But, by the time it concerns me more. There's some kind of feeling that pushing me to pay attention to it, and because the numbers also appear numerous times.

There was various explanation I've found. Some says, it's one way how spirits communicates, and other says it's a message from the universe to human. To give a life guidance maybe. I also heard, it's called angelic number.

Nowadays, I feel like to catch these similar numbers again. Actually, the feeling appear when I'm about to face, or was in a difficult time. Sometimes just when I get too centered over myself. Honestly, I just take it as precaution to get prepared or reflecting.

I'd like to hear others opinion about it, perhaps you have further info, or experience you'd like to share.

I would just think it's synchronicity if it happened to me. (The pun was unintentional by the way.) But I think things like that happen a bit more often with spirits, sentient servitors or spelled items around.

Agree with Lewk, but take this with a grain of salt:

I have been seeing 2:16 on the clock on the regular - AM and PM. It reminds me of my Baptist days. 216 is 6 x 6 x 6. /cackle/