TimeZone.IsDaylightSavingTime Method

Definition

Returns a value indicating whether a specified date and time is within a daylight saving time period.

Overloads

IsDaylightSavingTime(DateTime)

Returns a value indicating whether the specified date and time is within a daylight saving time period.

IsDaylightSavingTime(DateTime, DaylightTime)

Returns a value indicating whether the specified date and time is within the specified daylight saving time period.

IsDaylightSavingTime(DateTime)

Source:
TimeZone.cs
Source:
TimeZone.cs
Source:
TimeZone.cs

Returns a value indicating whether the specified date and time is within a daylight saving time period.

public virtual bool IsDaylightSavingTime (DateTime time);

Parameters

time
DateTime

A date and time.

Returns

true if time is in a daylight saving time period; otherwise, false.

Remarks

The year to which the daylight saving time period applies is derived from the time parameter.

Because the TimeZone class supports a single daylight saving time adjustment rule, the IsDaylightSavingTime(DateTime) method applies the current adjustment rule to any date, regardless of whether the adjustment rule was in effect on that date. Assuming that the operating system itself has accurate historic daylight saving time data, a more accurate result is available by using the TimeZoneInfo.IsDaylightSavingTime method. Whenever possible, use the TimeZoneInfo.IsDaylightSavingTime method.

See also

Applies to

.NET 9 和其他版本
产品 版本
.NET Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1

IsDaylightSavingTime(DateTime, DaylightTime)

Source:
TimeZone.cs
Source:
TimeZone.cs
Source:
TimeZone.cs

Returns a value indicating whether the specified date and time is within the specified daylight saving time period.

public static bool IsDaylightSavingTime (DateTime time, System.Globalization.DaylightTime daylightTimes);

Parameters

time
DateTime

A date and time.

daylightTimes
DaylightTime

A daylight saving time period.

Returns

true if time is in daylightTimes; otherwise, false.

Exceptions

daylightTimes is null.

Remarks

The TimeZoneInfo.IsDaylightSavingTime method provides the same functionality as this overload of the IsDaylightSavingTime method. Whenever possible, use the TimeZoneInfo.IsDaylightSavingTime method.

See also

Applies to

.NET 9 和其他版本
产品 版本
.NET Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1