| Not Specified | Time Zero Event (TZ0) is not specified or not received. If no Time Zero Event value is received, then this is the system default value. | | |
| Other | Time Zero Event (TZ0) is the some Other time value not in CV Terms. | | |
| Time of enrollment | Time Zero Event (TZ0) is the Time of enrollment. | | |
| Time of hospital admission | Time Zero Event (TZ0) is the Time of hospital admission | | |
| Time of infection | Time Zero Event (TZ0) is the Time of infection. | | |
| Time of initial treatment | Time Zero Event (TZ0) is the Time of initial treatment. | | |
| Time of initial vaccine administration | Time Zero Event (TZ0) is the Time of initial vaccine administration. | | |
| Time of transplantation | Time Zero Event (TZ0) is the Time of Transplantation. | | |