Is time and space only accompanied by texting and making phone calls?

Space-time companion is an epidemic prevention concept vocabulary. When the personal phone number and the confirmation number stay in the same space-time grid (the range is 800 m * 800 m) for more than 14 minutes, and the cumulative stay time of any number in the last 14 days exceeds 30 hours, the found number is the space-time companion number. At this time, the personal green health code will turn red with a warning.