procedure TForm1.Button1Click(Sender: TObject); begin Label1.Caption := FormatDateTime('hh:nn:ss', Now()); ... Label2.Caption := DateTimeToStr(Date()); Label3.Caption := FormatDateTime('yyyy年mm月dd日 hh时nn分ss秒', Now()); end;
FormatDateTime
日期加减
start_date := FormatDateTime('yyyy-MM-dd', Now()); end_date := FormatDateTime('yyyy-MM-dd', IncDay(Now)); end;
其中 IncDay
(或者 IncMonth
、IncYear
或者 IncHour
等,详见最下面的 RAD Studio 官方文档) 需要用到下面的单元 System.DateUtils:
System.DateUtils
在 Package rtl.bpl 中:
System.DateUtils
EDateTimeException ELocalTimeInvalid ELocalTimeInvalid is the exception class for invalid local times. TDateTimeHelper TTimeZone TTimeZone offers a set of tools for timezone support.
CompareDate Indicates the relationship between the date portions of two TDateTime values. CompareDateTime Indicates the relationship between two TDateTime values. CompareTime Indicates the relationship between the time portions of two TDateTime values. DateInRange Checks whether a TDate value is in range. DateOf Strips the time portion from a TDateTime value. DateTimeInRange Checks whether a TDateTime value is in range. DateTimeToJulianDate Converts a TDateTime value into a Julian date. DateTimeToMilliseconds DateTimeToModifiedJulianDate Converts a TDateTime value into a modified Julian date. DateTimeToUnix Converts a TDateTime value into a Unix/Linux-style date-and-time value. DateToISO8601 Converts the ADate date-and-time value, specified in the TDateTime format, into a string containing a date-and-time value in the ISO 8601 format. DayOf Returns the day of the month represented by a TDateTime value. DayOfTheMonth Returns the day of the month represented by a TDateTime value. DayOfTheWeek Returns the day of the week represented by a TDateTime value. DayOfTheYear Returns the number of days between a specified TDateTime value and December 31 of the previous year. DaysBetween Returns the number of whole days between two specified TDateTime values. DaysInAMonth Returns the number of days in a specified month of a specified year. DaysInAYear Returns the number of days in a specified year. DaysInMonth Returns the number of days in the month of a specified TDateTime value. DaysInYear Returns the number of days in the year of a specified TDateTime value. DaySpan Returns the number of days (including fractional days) between two specified TDateTime values. DecodeDateDay Returns the year and day of the year for a specified TDateTime. DecodeDateMonthWeek Returns the year, month, week of the month, and day of the week for a specified TDateTime. DecodeDateTime Returns Year, Month, Day, Hour, Minute, Second, and Millisecond values for a TDateTime. DecodeDateWeek Returns the year, week of the year, and day of the week for a specified TDateTime value object. DecodeDayOfWeekInMonth For a given TDateTime value, returns the year, month, day of the week, and the count of that day of the week in the month. EncodeDateDay Returns a TDateTime that represents a specified day of the year for a specified year. EncodeDateMonthWeek Returns a TDateTime that represents a specified day of a specified week in a specified month and year. EncodeDateTime Returns a TDateTime that represents a specified year, month, day, hour, minute, second, and millisecond. EncodeDateWeek Returns a TDateTime that represents a specified day of a specified week in a specified year. EncodeDayOfWeekInMonth Returns a TDateTime that represents a specified occurrence of a day of the week within a specified month and year. EndOfADay Returns a TDateTime that represents the last millisecond of a specified day. EndOfAMonth Returns a TDateTime that represents the last millisecond of the last day of a specified month. EndOfAWeek Returns a TDateTime object value that represents the last millisecond of a specified day of a specified week. EndOfAYear Returns a TDateTime that represents the last millisecond of a specified year. EndOfTheDay Returns a TDateTime that represents the last millisecond of the day identified by a specified TDateTime. EndOfTheMonth Returns a TDateTime that represents the last millisecond of the last day of the month identified by a specified TDateTime. EndOfTheWeek Returns a TDateTime that represents the last millisecond of the last day of the week identified by a specified TDateTime. EndOfTheYear Returns a TDateTime that represents the last millisecond of the last day of the year identified by a specified TDateTime. HourOf Returns the hour of the day represented by a TDateTime value. HourOfTheDay Returns the hour of the day represented by a TDateTime value. HourOfTheMonth Returns the number of hours between a specified TDateTime value and 12:00 A.M. of the first day of the month. HourOfTheWeek Returns the number of hours between a specified TDateTime value and 12:00 A.M. of the first day of the week. HourOfTheYear Returns the number of hours between a specified TDateTime value and 12:00 A.M. of the first day of the year. HoursBetween Returns the number of whole hours between two specified TDateTime values. HourSpan Returns the number of hours (including fractional hours) between two specified TDateTime values. HttpToDate IncDay Returns a date shifted by a specified number of days. IncHour Returns a date/time value shifted by a specified number of hours. IncMilliSecond Returns a date/time value shifted by a specified number of milliseconds. IncMinute Returns a date/time value shifted by a specified number of minutes. IncSecond Returns a date/time value shifted by a specified number of seconds. IncWeek Returns a date shifted by a specified number of weeks. IncYear Returns a date shifted by a specified number of years. InvalidDateDayError InvalidDateDayError is used internally. InvalidDateMonthWeekError InvalidDateMonthWeekError is used internally. InvalidDateTimeError InvalidDateTimeError is used internally. InvalidDateWeekError InvalidDateWeekError is used internally. InvalidDayOfWeekInMonthError InvalidDayOfWeekInMonthError is used internally. IsAM Indicates whether the time portion of a specified TDateTime value occurs before noon. IsInLeapYear Indicates whether a specified TDateTime value occurs in a leap year. ISO8601ToDate Converts the AISODate date-and-time value, specified in the ISO 8601 format, into the date-and-time value in the TDateTime format. IsPM Indicates whether the time portion of a specified TDateTime value occurs in the afternoon. IsSameDay Indicates whether a specified TDateTime value occurs on a the same day as a criterion date. IsToday Indicates whether a specified TDateTime value occurs on the current date. IsValidDate Indicates whether a specified year, month, and day represent a valid date. IsValidDateDay Indicates whether a specified year and day of the year represent a valid date. IsValidDateMonthWeek Indicates whether a specified year, month, week of the month, and day of the week represent a valid date. IsValidDateTime Indicates whether a specified year, month, day, hour, minute, second, and millisecond represent a valid date and time. IsValidDateWeek Indicates whether a specified year, week of the year, and day of the week represent a valid date. IsValidTime Indicates whether a specified hour, minute, second, and millisecond represent a valid date and time. JulianDateToDateTime Converts a Julian date to a TDateTime value. MilliSecondOf Returns the millisecond of the second represented by a TDateTime value. MilliSecondOfTheDay Returns the number of milliseconds between a specified TDateTime value and the beginning of the same day. MilliSecondOfTheHour Returns the number of milliseconds between a specified TDateTime value and the beginning of the same hour. MilliSecondOfTheMinute Returns the number of milliseconds between a specified TDateTime value and the beginning of the same minute. MilliSecondOfTheMonth Returns the number of milliseconds between a specified TDateTime value and the beginning of the month. MilliSecondOfTheSecond Returns the millisecond of the second represented by a TDateTime value. MilliSecondOfTheWeek Returns the number of milliseconds between a specified TDateTime value and 12:00:00:00 A.M. of the first day of the week. MilliSecondOfTheYear Returns the number of milliseconds between a specified TDateTime value and 12:00:00:00 A.M. of the first day of the year. MilliSecondsBetween Returns the number of milliseconds between two specified TDateTime values. MilliSecondSpan Returns the number of milliseconds between two specified TDateTime values. MinuteOf Returns the minute of the hour represented by a TDateTime value. MinuteOfTheDay Returns the number of minutes between a specified TDateTime value and 12:00 A.M. of the same day. MinuteOfTheHour Returns the number of minutes between a specified TDateTime value and the beginning of the same hour. MinuteOfTheMonth Returns the number of minutes between a specified TDateTime value and 12:00 A.M. of the first day of the month. MinuteOfTheWeek Returns the number of minutes between a specified TDateTime value and 12:00 A.M. of the first day of the week. MinuteOfTheYear Returns the number of minutes between a specified TDateTime value and 12:00 A.M. of the first day of the year. MinutesBetween Returns the number of minutes between two specified TDateTime values. MinuteSpan Returns the number of minutes, including fractions thereof, between two specified TDateTime values. ModifiedJulianDateToDateTime Converts a modified Julian date to a TDateTime value. MonthOf Returns the month of the year represented by a TDateTime value. MonthOfTheYear Returns the month of the year represented by a TDateTime value. MonthsBetween Returns the approximate number of months between two specified TDateTime values. MonthSpan Returns the approximate number of months, including fractions, between two specified TDateTime values. NthDayOfWeek Returns the weekday of the specified TDateTime value. RecodeDate Selectively replaces the date parts of a specified TDateTime value. RecodeDateTime Selectively replaces parts of a specified TDateTime value. RecodeDay Replaces the day of the month for a specified TDateTime value. RecodeHour Replaces the hour of the day for a specified TDateTime value. RecodeMilliSecond Replaces the millisecond of the second for a specified TDateTime value. RecodeMinute Replaces the minute of the hour for a specified TDateTime value. RecodeMonth Replaces the month of the year for a specified TDateTime value. RecodeSecond Replaces the second of the minute for a specified TDateTime value. RecodeTime Selectively replaces the time parts of a specified TDateTime value. RecodeYear Replaces the year for a specified TDateTime value. SameDate Indicates whether two TDateTime values represent the same year, month, and day. SameDateTime Indicates whether two TDateTime values represent the same year, month, day, hour, minute, second, and millisecond. SameTime Indicates whether two TDateTime values represent the same time of day, ignoring the date portion. SecondOf Returns the second of the minute represented by a TDateTime value. SecondOfTheDay Returns the number of seconds between a specified TDateTime value and 12:00:00 A.M. of the same day. SecondOfTheHour Returns the number of seconds between a specified TDateTime value and the beginning of the same hour. SecondOfTheMinute Returns the number of seconds between a specified TDateTime value and the beginning of the same minute. SecondOfTheMonth Returns the number of seconds between a specified TDateTime value and 12:00:00 A.M. on the first day of the month. SecondOfTheWeek Returns the number of seconds between a specified TDateTime value and 12:00:00 A.M. of the first day of the week. SecondOfTheYear Returns the number of seconds between a specified TDateTime value and 12:00:00 A.M. on the first day of the year. SecondsBetween Returns the number of seconds between two specified TDateTime values. SecondSpan Returns the number of seconds (including fractions thereof) between two specified TDateTime values. StartOfADay Returns a TDateTime that represents 12:00:00:00 A.M. on a specified day. StartOfAMonth Returns a TDateTime that represents 12:00:00:00 A.M. on the first day of a specified month. StartOfAWeek Returns a TDateTime that represents the first moment on a specified day of a specified week. StartOfAYear Returns a TDateTime that represents the first moment on the first day of a specified year. StartOfTheDay Returns a TDateTime that represents 12:00:00:00 A.M. on the day identified by a specified TDateTime. StartOfTheMonth Returns a TDateTime that represents 12:00:00:00 A.M. on the first day of the month identified by a specified TDateTime. StartOfTheWeek Returns a TDateTime that represents 12:00:00:00 A.M. on the first day of the week identified by a specified TDateTime. StartOfTheYear Returns a TDateTime that represents 12:00:00:00 A.M. on the first day of the year identified by a specified TDateTime. TimeInRange Checks whether a TDateTime value is in range. TimeOf Strips the date portion from a TDateTime value. TimeToMilliseconds Today Returns a TDateTime value that represents the current date. Tomorrow Returns a TDateTime value that represents the following day. TryEncodeDateDay Calculates the TDateTime value that represents a specified day of the year for a specified year. TryEncodeDateMonthWeek Calculates the TDateTime value that represents a specified day of a specified week in a specified month and year. TryEncodeDateTime Calculates the TDateTime value that represents a specified year, month, day, hour, minute, second, and millisecond. TryEncodeDateWeek Calculates the TDateTime value that represents a specified day of a specified week in a specified year. TryEncodeDayOfWeekInMonth Calculates a TDateTime that represents a specified occurrence of a day of the week within a specified month and year. TryISO8601ToDate Tries to convert the provided date-and-time value, specified in the ISO 8601 format, into the date-and-time value in the TDateTime format. Returns True if the conversion succeeds. TryJulianDateToDateTime Converts a Julian date to a TDateTime value. TryModifiedJulianDateToDateTime Converts a modified Julian date to a TDateTime value. TryRecodeDateTime Selectively replaces parts of a specified TDateTime value. UnixToDateTime Converts a Unix/Linux style date-and-time value to a TDateTime value. WeekOf Returns the week of the year represented by a TDateTime value. WeekOfTheMonth Returns the week of the month represented by a TDateTime value. WeekOfTheYear Returns the week of the year represented by a TDateTime value. WeeksBetween Returns the number of whole weeks between two specified TDateTime values. WeeksInAYear Returns the number of weeks in a specified year. WeeksInYear Returns the number of weeks in the year of a specified TDateTime value. WeekSpan Returns the number of weeks (including fractional weeks) between two specified TDateTime values. WithinPastDays Indicates whether two dates are within a specified number of days of each other. WithinPastHours Indicates whether two date/time values are within a specified number of hours of each other. WithinPastMilliSeconds Indicates whether two date/time values are within a specified number of milliseconds of each other. WithinPastMinutes Indicates whether two date/time values are within a specified number of minutes of each other. WithinPastMonths Indicates whether two date/time values are within a specified number of months of each other. WithinPastSeconds Indicates whether two date/time values are within a specified number of seconds of each other. WithinPastWeeks Indicates whether two date/time values are within a specified number of weeks of each other. WithinPastYears Indicates whether two date/time values are within a specified number of years of each other. YearOf Returns the year represented by a TDateTime value. YearsBetween Returns the approximate number of years between two specified TDateTime values. YearSpan Returns the approximate number of years (including fractions thereof) between two specified TDateTime values. Yesterday Returns a TDateTime value that represents the preceding day.
TLocalTimeType Specifies the type of a date and time value.