Class TzdbDateTimeZoneSource
Implements
Inherited Members
Namespace: NodaTime.TimeZones
Assembly: NodaTime.dll
Syntax
public sealed class TzdbDateTimeZoneSource : IDateTimeZoneSource
Remarks
Properties
Aliases
Declaration
public ILookup<string, string> Aliases { get; }
Property Value
Type | Description |
---|---|
ILookup<string, string> | A lookup from canonical ID to the aliases of that ID. |
Remarks
CanonicalIdMap
Declaration
public IDictionary<string, string> CanonicalIdMap { get; }
Property Value
Type | Description |
---|---|
IDictionary<string, string> | A map from time zone ID to the canonical ID. |
Remarks
This map contains an entry for every ID returned by GetIds(), where canonical IDs map to themselves.
The returned map is read-only; any attempts to call a mutating method will throw NotSupportedException.
Default
Declaration
public static TzdbDateTimeZoneSource Default { get; }
Property Value
Type | Description |
---|---|
TzdbDateTimeZoneSource | The source initialised from resources within the NodaTime assembly. |
Remarks
TzdbToWindowsIds
Declaration
public IReadOnlyDictionary<string, string> TzdbToWindowsIds { get; }
Property Value
Type | Description |
---|---|
IReadOnlyDictionary<string, string> |
Remarks
Where a TZDB alias isn't present directly in the Windows mapping, but its canonical ID is, the dictionary will contain an entry for the alias as well. For example, the TZDB ID "Africa/Asmara" is an alias for "Africa/Nairobi", which has a Windows ID of "E. Africa Standard Time". "Africa/Asmara" doesn't appear in the Windows mapping directly, but it will still be present in the returned dictionary.
Where a TZDB canonical ID isn't present in the Windows mapping, but an alias is, the dictionary will contain an entry for the canonical ID as well. For example, the Windows mapping uses the TZDB ID "Asia/Calcutta" for "India Standard Time". This is an alias for "Asia/Kolkata" in TZDB, so the returned dictionary will have an entry mapping "Asia/Kolkata" to "Asia/Calcutta". If multiple aliases for the same canonical ID have entries in the Windows mapping with different Windows IDs, the alias that is earliest in lexicographical ordering determines the value for the entry.
If a canonical ID is not present in the mapping, nor any of its aliases, it will not be present in the returned dictionary.
TzdbVersion
Declaration
public string TzdbVersion { get; }
Property Value
Type | Description |
---|---|
string | The TZDB version (e.g. "2013a") of the source data. |
Remarks
VersionId
Declaration
public string VersionId { get; }
Property Value
Type | Description |
---|---|
string | An appropriate version ID for diagnostic purposes. |
Remarks
This source returns a string such as "TZDB: 2013b (mapping: 8274)" corresponding to the versions of the tz database and the CLDR Windows zones mapping file.
Note that there is no need to parse this string to extract any of the above information, as it is available directly from the TzdbVersion and Version properties.
WindowsMapping
Declaration
public WindowsZones WindowsMapping { get; }
Property Value
Type | Description |
---|---|
WindowsZones | The Windows time zone mapping information provided in the CLDR supplemental "windowsZones.xml" file. |
Remarks
WindowsToTzdbIds
Declaration
public IReadOnlyDictionary<string, string> WindowsToTzdbIds { get; }
Property Value
Type | Description |
---|---|
IReadOnlyDictionary<string, string> |
Remarks
Zone1970Locations
Declaration
public IList<TzdbZone1970Location>? Zone1970Locations { get; }
Property Value
Type | Description |
---|---|
IList<TzdbZone1970Location> | A read-only list of zone locations known to this source. |
Remarks
This location data differs from ZoneLocations in two important respects:
- Where multiple similar zones exist but only differ in transitions before 1970, this location data chooses one zone to be the canonical "post 1970" zone.
- This location data can represent multiple ISO-3166 country codes in a single entry. For example, the entry corresponding to "Europe/London" includes country codes GB, GG, JE and IM (Britain, Guernsey, Jersey and the Isle of Man, respectively).
Every zone location's time zone ID is guaranteed to be valid within this source (assuming the source has been validated).
ZoneLocations
Declaration
public IList<TzdbZoneLocation>? ZoneLocations { get; }
Property Value
Type | Description |
---|---|
IList<TzdbZoneLocation> | A read-only list of zone locations known to this source. |
Remarks
Methods
ForId(string)
Declaration
public DateTimeZone ForId(string id)
Parameters
Type | Name | Description |
---|---|---|
string | id | The ID of the time zone to return. This must be one of the IDs returned by GetIds(). |
Returns
Type | Description |
---|---|
DateTimeZone | The DateTimeZone for the given ID. |
Remarks
Note that this is permitted to return a DateTimeZone that has a different ID to that requested, if the ID provided is an alias.
Note also that this method is not required to return the same DateTimeZone instance for successive requests for the same ID; however, all instances returned for a given ID must compare as equal.
It is advised that sources should document their behaviour regarding any fixed-offset timezones (i.e. "UTC" and "UTC+/-Offset") that are included in the list returned by GetIds(). (These IDs will not be requested by DateTimeZoneCache, but any users calling into the source directly may care.)
The source need not attempt to cache time zones; caching is typically provided by DateTimeZoneCache.
Exceptions
Type | Condition |
---|---|
ArgumentException | id is not supported by this source. |
FromStream(Stream)
Declaration
public static TzdbDateTimeZoneSource FromStream(Stream stream)
Parameters
Type | Name | Description |
---|---|---|
Stream | stream | The stream containing time zone data |
Returns
Type | Description |
---|---|
TzdbDateTimeZoneSource | A TzdbDateTimeZoneSource providing information from the given stream. |
Remarks
The stream is not closed by this method, but will be read from without rewinding. A successful call will read the stream to the end.
See the user guide for instructions on how to generate an updated time zone database file from a copy of the (textual) tz database.
Exceptions
Type | Condition |
---|---|
InvalidNodaDataException | The stream contains invalid time zone data, or data which cannot be read by this version of Noda Time. |
IOException | Reading from the stream failed. |
InvalidOperationException | The supplied stream doesn't support reading. |
GetIds()
Declaration
public IEnumerable<string> GetIds()
Returns
Type | Description |
---|---|
IEnumerable<string> | The IDs available from this source. |
Remarks
Every value in this enumeration must return a valid time zone from ForId(string) for the life of the source. The enumeration may be empty, but must not be null, and must not contain any elements which are null. It should not contain duplicates: this is not enforced, and while it may not have a significant impact on clients in some cases, it is generally unfriendly. The built-in implementations never return duplicates.
The source is not required to provide the IDs in any particular order, although they should be distinct.
Note that this list may optionally contain any of the fixed-offset timezones (with IDs "UTC" and "UTC+/-Offset"), but there is no requirement they be included.
GetSystemDefaultId()
Declaration
public string? GetSystemDefaultId()
Returns
Type | Description |
---|---|
string | The ID for the system default time zone for this source, or null if the system default time zone has no mapping in this source. |
Remarks
Validate()
Declaration
public void Validate()
Remarks
NodaTime.TzdbCompiler
(including the data shipped with Noda Time)
will already have been validated via this method when it was originally produced. This method should
only normally be called explicitly if you have data from a source you're unsure of.
Exceptions
Type | Condition |
---|---|
InvalidNodaDataException | The source data is invalid. The source may not function correctly. |