How many hours is CST behind NZST?
As abbreviations, NZST is always 18 hours ahead of CST: CST is UTC−6 and NZST is UTC+12. To convert, add 18 hours.
Check which label you actually need: NZST (New Zealand Time is on NZDT today). A time written with an abbreviation that is not in use is usually meant as the local time, so convert between the places instead: right now NZST is 19 hours ahead of CST.
When the CST to NZST time difference changes
For most of the year NZST is 17 hours ahead of CST. From 1 November to 31 December 2026, NZST is 19 hours ahead of CST instead, because the two places change their clocks on different dates. Meetings booked by the usual gap land an hour off in those weeks.
| Dates | NZST vs CST | Length |
|---|---|---|
| 1 November 2026 to 31 December 2026 | 19 hours ahead | 61 days |
| 1 January 2027 to 13 March 2027 | 19 hours ahead | 72 days |
| 14 March 2027 to 3 April 2027 | 18 hours ahead | 21 days |
| 4 April 2027 to 25 September 2027 | 17 hours ahead | 175 days |
| 26 September 2027 to 6 November 2027 | 18 hours ahead | 42 days |
| 7 November 2027 to 31 December 2027 | 19 hours ahead | 55 days |
Calling hours for CST and NZST
- When NZST is 17 hours ahead of CST: no shared 09:00 to 17:00 hours; one side has to take the call outside office hours.
- When NZST is 19 hours ahead of CST: no shared 09:00 to 17:00 hours; one side has to take the call outside office hours.
- When NZST is 18 hours ahead of CST: no shared 09:00 to 17:00 hours; one side has to take the call outside office hours.