struct CivilTransition

TimeZone::NextTransition()

TimeZone::PrevTransition()

Finds the time of the next/previous offset change in this time zone.

By definition, `NextTransition(t,

&trans

)` returns false when `t` is

`InfiniteFuture()`, and `PrevTransition(t,

&trans

)` returns false

when `t` is `InfinitePast()`. If the zone has no transitions, the

result will also be false no matter what the argument.

Otherwise, when `t` is `InfinitePast()`, `NextTransition(t,

&trans

)`

returns true and sets `trans` to the first recorded transition. Chains

of calls to `NextTransition()/PrevTransition()` will eventually return

false, but it is unspecified exactly when `NextTransition(t,

&trans

)`

jumps to false, or what time is set by `PrevTransition(t,

&trans

)` for

a very distant `t`.

Note: Enumeration of time-zone transitions is for informational purposes

only. Modern time-related code should not care about when offset changes

occur.

Example:

absl::TimeZone nyc;

if (!absl::LoadTimeZone("America/New_York",

&nyc

)) { ... }

const auto now = absl::Now();

auto t = absl::InfinitePast();

absl::TimeZone::CivilTransition trans;

while (t

<

= now

&

&

nyc.NextTransition(t,

&trans

)) {

// transition: trans.from -> trans.to

t = nyc.At(trans.to).trans;

}