CkDateTime Lazarus Pascal Reference Documentation
CkDateTime
Current Version: 11.6.0
CkDateTime represents a date/time value and provides conversion methods for common date/time formats, including .NET DateTime, DateTime ticks, RFC 822, RFC 3339 / ISO 8601-style timestamps, Unix time, DOS date/time, OLE DATE, NTP time, ULID timestamps, and Chilkat DtObj. It also supports date arithmetic, age/expiration checks, serialization, and local/UTC conversion.
For an extended overview, see CkDateTime Class Overview
Create / Free
uses
Chilkat.CkDateTime;
var
obj: TCkDateTime;
begin
obj := TCkDateTime.Create;
try
if not obj.IsValid then
raise Exception.Create('Failed to create a TCkDateTime instance.');
// ... use obj ...
finally
obj.Free;
end;
end;
Allocates the underlying CkDateTime object and returns a new TCkDateTime instance. Simply adding Chilkat.CkDateTime to the unit's uses clause is enough to locate and bind to the Chilkat shared library (DLL / .so / .dylib) at runtime — no separate load step is required. Check obj.IsValid after calling Create; it is False if the underlying library could not be found/loaded or the object could not be allocated (for example, when unlicensed).
Every TCkDateTime created by calling Create should eventually be released by calling .Free (inherited from TObject). The destructor automatically disposes the underlying CkDateTime handle. A native (unmanaged) memory leak occurs if the object is never freed.
Properties
DebugLogFilePath
If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.
Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.
Possible causes of hangs include:
- A timeout property set to 0, indicating an infinite timeout.
- A hang occurring within an event callback in the application code.
- An internal bug in the Chilkat code causing the hang.
IsDst
This is the Daylight Saving Time flag. It can have one of three possible values: 1, 0, or -1. It has the value 1 if Daylight Saving Time is in effect, 0 if Daylight Saving Time is not in effect, and -1 if the information is not available.
Note: This is NOT the DST for the current system time. It is the DST that was in effect at the date value contained in this object.
topLastErrorHtml
Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastErrorText
Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
LastErrorXml
Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.
topLastMethodSuccess
Indicates the success or failure of the most recent method call: True means success, False means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.
UtcOffset
For the current system's timezone, returns the number of seconds offset from UTC for this date/time. The offset includes daylight savings adjustment. Local timezones west of UTC return a negative offset.
topVerboseLogging
If set to True, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is False. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.
Version
Methods
AddDays
Adds an integer number of days to the date/time. To subtract days, pass a negative integer.
Returns True for success, False for failure.
topAddSeconds
Adds an integer number of seconds to the date/time. To subtract seconds, pass a negative integer.
Returns True for success, False for failure.
DeSerialize
Loads the date/time with a string having the format as produced by the Serialize method, which is a string of SPACE separated integers containing (in this order) year, month, day, hour, minutes, seconds, and a UTC flag having the value of 1/0.
topDiffSeconds
function DiffSeconds(dateTimeArg: TChilkatBase): Integer;
Returns the difference in seconds between the dateTimeArg and this date/time. The value returned is this object's date/time - dateTimeArg's date/time. For example, if the returned value is positive, then this object's date/time is more recent than dateTimeArg's date/time. If the return value is negative, then this object's date/time is older than dateTimeArg's date/time.
ExpiresWithin
const units: string): Boolean;
Returns True if the date/time is within n seconds/minutes/hours/days of the current system date/time. Otherwise returns False. The units can be seconds, minutes, hours, or days (plural or singular).
GetAsDateTimeTicks
Returns the date/time as a 64-bit integer .NET DateTime value.
bLocal indicates whether a local or UTC time is returned.
This is a date and time expressed in the number of 100-nanosecond intervals that have elapsed since January 1, 0001 at 00:00:00.000 in the Gregorian calendar.
The DateTime value type represents dates and times with values ranging from 12:00:00 midnight, January 1, 0001 Anno Domini (Common Era) through 11:59:59 P.M., December 31, 9999 A.D. (C.E.).
Time values are measured in 100-nanosecond units called ticks, and a particular date is the number of ticks since 12:00 midnight, January 1, 0001 A.D. (C.E.) in the GregorianCalendar calendar (excluding ticks that would be added by leap seconds). For example, a ticks value of 31241376000000000L represents the date, Friday, January 01, 0100 12:00:00 midnight. A DateTime value is always expressed in the context of an explicit or default calendar.
topGetAsDosDate
Returns the date/time as a 32-bit DOS date/time bitmask.
bLocal indicates whether a local or UTC time is returned.
The DOS date/time format is a bitmask:
24 16 8 0 +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ |Y|Y|Y|Y|Y|Y|Y|M| |M|M|M|D|D|D|D|D| |h|h|h|h|h|m|m|m| |m|m|m|s|s|s|s|s| +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ \___________/\________/\_________/ \________/\____________/\_________/ year month day hour minute second
The year is stored as an offset from 1980. Seconds are stored in two-second
increments. (So if the second value is 15, it actually represents 30 seconds.)
GetAsIso8601
bLocal: Boolean): string;
Returns the date/time in a compatible ISO 8601 format according to the format specified in formatStr.. Examples of ISO 8601 formats include the following:
YYYY-MM-DD
YYYY-MM-DDThh:mmTZD
YYYY-MM-DDThh:mm:ssTZD
YYYY-MM-DDThh:mm:ss:sssTZD
For the date portion of these formats, YYYY is a four-digit year representation, MM is a two-digit month, and DD is a two-digit day. For the time portion, hh is the hour in 24-hour notation, mm is the two-digit minutes, ss is the two-digit seconds, and sss is the 3-digit milliseconds. A time designator T separates the date and time portions of the string, while a time zone designator TZD specifies a time zone (UTC).
bLocal indicates whether a local or UTC time is returned.
Returns True for success, False for failure.
GetAsOleDate
Returns the date/time in a Windows OLE DATE format.
bLocal indicates whether a local or UTC time is returned.
The OLE automation date format is a floating point value, counting days since midnight 30 December 1899. Hours and minutes are represented as fractional days.
topGetAsRfc822
Returns the date/time as an RFC822 formatted string. (An RFC822 format string is what is found in the Date header field of an email, such as Wed, 18 Oct 2017 09:08:21 GMT.)
bLocal indicates whether a local or UTC time is returned.
Returns True for success, False for failure.
topGetAsTimestamp
Returns the date/time as an RFC 3339 formatted string, such as 1990-12-31T23:59:60Z.
(This is an ISO 8061 format like the following: YYYY-MM-DDThh:mm:ssTZD)
bLocal indicates whether a local or UTC time is returned.
Returns True for success, False for failure.
GetAsUnixTime
Returns the date/time as a Unix time value, which is the number of seconds elapsed since 00:00:00 UTC on January 1, 1970.
bLocal indicates whether the date/time returned is local or UTC.
GetAsUnixTime64
The same as GetUnixTime, except returns the date/time as a 64-bit integer.
bLocal indicates whether a local or UTC time is returned.
Note: 64-bit integers are needed after Jan 19, 2038. The Y2038 problem happens because some systems store Unix time as a signed 32-bit number of seconds since Jan 1, 1970. This number runs out on Jan 19, 2038, causing the time to wrap around to a date in 1901.
topGetAsUnixTimeDbl
The same as GetUnixTime, except returns the date/time as a double.
bLocal indicates whether a local or UTC time is returned.
GetAsUnixTimeStr
Returns the time in Unix format (in seconds since the epoch: 00:00:00 UTC on 1 January 1970).
bLocal indicates whether the date/time returned is local or UTC.
Returns True for success, False for failure.
LoadTaskResult
function LoadTaskResult(task: TChilkatBase): Boolean;
Loads the date/time from a completed asynchronous task.
Returns True for success, False for failure.
topOlderThan
const units: string): Boolean;
Returns True if the date/time is older than the current system date/time by n seconds/minutes/hours/days. Otherwise returns False. The units can be seconds, minutes, hours, or days (plural or singular).
Serialize
Serializes the date/time to a us-ascii string that can be imported at a later time via the DeSerialize method. The format of the string returned by this method is not intended to match any published standard. It is formatted to a string with SPACE separated integers containing (in this order) year, month, day, hour, minutes, seconds, and a UTC flag having the value of 1 or 0.
Returns True for success, False for failure.
topSetFromCurrentSystemTime
Sets the date/time from the current system time.
topSetFromDateTimeTicks
ticks: Int64): Boolean;
Sets the date/time from a .NET DateTime value represented in ticks. See GetAsDateTimeTicks for more information.
bLocal indicates whether the passed in date/time is local or UTC.
SetFromDosDate
t: LongWord): Boolean;
Sets the date/time from a 32-bit DOS date/time bitmask. See GetAsDosDate for more information.
topSetFromDtObj
function SetFromDtObj(dt: TChilkatBase): Boolean;
SetFromNtpServer
Sets the date/time by sending a query to an NTP server.
Returns True for success, False for failure.
SetFromNtpTime
Sets the date/time from a 32-bit NTP time value. ntpSeconds is the number of seconds since 00:00 (midnight) 1 January 1900 GMT.
SetFromOleDate
dt: Double): Boolean;
Sets the date/time from a Windows OLE DATE value.
bLocal indicates whether the passed in date/time is local or UTC.
Note: This method was not working correctly. The problem was discovered just after releasing v9.5.0.65. It will be fixed in the next version update.
topSetFromRfc822
Sets the date/time from an RFC822 date/time formatted string. Here are some examples of RFC822 formatted date/times:
Tue, 15 Nov 2022 22:00:58 +0000 Tue, 15 Nov 2022 20:21:50 +0100 Tue, 01 Nov 2022 18:09:41 -0600
Returns True for success, False for failure.
topSetFromTimestamp
Sets the date/time from an RFC 3339 timestamp format. (such as 1990-12-31T23:59:60Z:)
(This is an ISO 8061 format like the following: YYYY-MM-DDThh:mm:ssTZD)
Note: Starting in v9.5.0.77, strings formatted as YYMMDDhhmmssZ, such as 181221132225Z, can also be passed to this method.
Returns True for success, False for failure.
SetFromUlid
const ulid: string): Boolean;
Sets this object's date/time using the timestamp embedded in the ulid. If the ulid was not a valid ULID, returns False and the date/time is not set. bLocal indicates whether the ulid uses a local time or UTC time.
Returns True for success, False for failure.
SetFromUnixTime
t: LongWord): Boolean;
Sets the date/time from a UNIX time value.
bLocal indicates whether the passed in date/time is local or UTC.
SetFromUnixTime64
t: Int64): Boolean;
The same as SetFromUnixTime, except that it uses a 64-bit integer to solve the Y2038 problem.
bLocal indicates whether the passed in date/time is local or UTC.
Note: 64-bit integers are needed after Jan 19, 2038. The Y2038 problem happens because some systems store Unix time as a signed 32-bit number of seconds since Jan 1, 1970. This number runs out on Jan 19, 2038, causing the time to wrap around to a date in 1901.
topSetFromUnixTimeDbl
d: Double): Boolean;
The same as SetFromUnixTime, except that it uses a double to solve the Y2038 problem. (See GetAsUnixTime for more information about Y2038).
bLocal indicates whether the passed in date/time is local or UTC.
ToDtObj
procedure ToDtObj(bLocal: Boolean;
dtObj: TChilkatBase);
Copies the date/time to the dtObj. Gets the date/time in the local time if bLocal is True, or GMT if bLocal is False.
UlidGenerate
Generates and returns a new ULID using this object's date/time value. bLocal indicates whether to use local time or UTC time.
Returns True for success, False for failure.
UlidIncrement
function UlidIncrement(ulid: TChilkatBase): Boolean;
UlidValidate
Validates the ulid. Returns True if the ulid is valid, otherwise returns False.
Returns True for success, False for failure.