Standby and wait time
Wait time gets recomputed against your own terms: the free window, the rate that applies after it, and where the clock starts. When your terms don't say, we don't guess. We only claim what the paper proves.
One corpus invoice bills standby by the minute: 30 minutes at $0.91 a minute, 36 minutes at the same rate, both exact to the penny against the terms printed on that invoice. Most ready-mix jobs aren't billed that explicitly, which is exactly why silence gets flagged, not priced.