Time-stamped, documented events such as receipts, time cards, phone records or attendance registers, which are more reliable than memory.
It indicates the general area a phone connected from, not an exact location, and device clocks can be wrong.
Record both versions with their sources, check how each witness anchored the time and avoid choosing one without corroboration.
No. It is a lead to examine carefully, not evidence that the person was involved in what happened.
Use time ranges and confidence levels, and mark unknown gaps clearly instead of filling them with assumptions.