Time zones and daylight saving

Enter the time exactly as it was on the clock where you were born. Do not convert it to UTC, and do not subtract an hour for summer time. The app does that, using the rules that were actually in force on that date in that place.

Why this matters more than it sounds

Time-zone history is genuinely strange. Countries have moved zones, split them, adopted year-round summer time, applied double summer time in wartime, and switched on dates that changed from year to year. A chart calculated with today's rules applied to a 1962 birth can be an hour out — and an hour is enough to move the Moon by half a gate and to change your lines.

The app resolves the offset from the historical time-zone database for the coordinates attached to the city you selected. That is why the form insists you pick a city from the list rather than typing one.

The cases that catch people out

• Births during a summer-time change. In the hour that repeats when clocks go back, the same clock time occurs twice. If you were born in that hour, the app resolves one of them. It is a rare case and usually shifts nothing, but if your chart sits on a boundary it is worth knowing.
• Births just after midnight. The date matters as much as the time. If the birth certificate says 00:20, check which day it records.
• Countries that changed zone entirely. Some regions moved offset permanently. Selecting the right city handles it; selecting a large city in a neighbouring country does not.

What to do if you suspect the zone is wrong

The form shows the resolved zone under the place field once you have picked. Check it reads as you would expect. If it does not, you may have selected a same-named city elsewhere — there are eight Springfields and several Cambridges.

Reopen Account → Birth data, clear the place, retype, and choose carefully. The chart recalculates on save.