Dealing with date in prolog - date

How to make a program where you can insert a date, and after add some days (suppose + 20 days) to obtain a new date?
EXAMPLE:
?- write a date in this format(YYYY-MM-DD.): 2020-01-15.
The new date is : 2020-02-04
I think that I should use this predefined predicates: date time stamp, stamp date time and date time value but I dont succeed to manage it.
I found below code :
goes :-
write('Please enter your birthday [YYYY-MM-DD]'),
nl,
read_string(Birthday),
parse_time(Birthday, Stamp),
stamp_date_time(Stamp, DateTime, 'UTC'),
DateTime = date(Year, Month, Day, _, _, _, _, _, _),
print('Year: '), print(Year), nl,
print('Month: '), print(Month), nl,
print('Day: '), print(Day), nl.
read_string(String) :-
current_input(Input),
read_line_to_codes(Input, Codes),
string_codes(String, Codes).
and get this:
?- goes.
Please enter your birthday [YYYY-MM-DD] |: 2010-07-05.
false.

The building blocks are all there:
?- date_time_stamp(date(2020,4,15,0,0,0,Off,TZ,DST),TimeStamp).
Off = -7200,
TZ = 'CEST',
DST = true,
TimeStamp = 1586901600.0.
?- NDays=20,Next is $TimeStamp+60*60*24*NDays.
NDays = 20,
Next = 1588629600.0,
TimeStamp = 1586901600.0.
?- stamp_date_time($Next,DT,local).
DT = date(2020, 5, 5, 0, 0, 0.0, -7200, 'CEST', true),
Next = 1588629600.0.
The notation $TimeStamp is a SWI-Prolog handly feature of the REPL (that is, the interactive interpreter), that give us the last value that the variable TimeStamp has been binded.
Clearly, you're better to encapsulate the complexity in your own applicative interface.
The documentation also hints a different way, just add the number of days to the day field of the date/9 structure, to get the appropriate timestamp.
Then the whole could be:
goes :-
write('enter date as `YYYY-MM-DD.`:'),
read(YYYY-MM-DD),
D1 is DD+20,
date_time_stamp(date(YYYY,MM,D1,0,0,0,_,_,_),Stamp),
stamp_date_time(Stamp,D,local),
date_time_value(date,D,DV),
format('result date:~w', [DV]).

Related

Format date range for next year

I'm trying to get a date range that takes the calendar year after the transaction date. Say if the date was this year then it should be 1/01/2018 - 12/31/2018.
I'm using this syntax but am getting the error that everything after the first line is not part of the formula. Any ideas?
Local DateVar d := CDate cstr(year({TransDate}));
Local DateVar Range dr := DateSerial (Year(d)+ 1, Month(d) - 1, 1) To
DateSerial (Year(d)+ 1, Month(d) - 1, 1);
You're missing parentheses for CDate in your first line. Proper syntax would be:
Local DateVar d := CDate(cstr(year({?Start Date})));
However that still won't work, because the result of a formula cannot be a date range. Instead, separate the range into a StartDate and EndDate field, then use those for your calculations.
StartDate: DateSerial(Year({?Date}) + 1, 1, 1)
EndDate: DateSerial(Year({?Date}) + 1, 12, 31)

Convert year and month variables to timestamp in Postgresql

I have to variables: year and month, both of type integer.
E.g:
year = 2016
month = 1
I want to, in my select statement, return a timestamp given those two variables.
I've had a look at the documentation, specifically to_timestamp and to_date, but all the examples I've come across show a string being converted into a timestamp.
I do not really want to convert my year and month into a string, such as:
to_timestamp(to_char(int,year) + ' ' + to_char(int, month),YYYY/MM/DD HH24:MI:SS)
So, how can I (if it is possible) convert my year and month into a timestamp?
If you are using Postgres 9.4 or later, you could try using make_timestamp():
make_timestamp(2016, 1, 1, 0, 0, 0.0)
This would create a timestamp for January 1, 2016 at midnight. We need to specify values for the other components, even if they end up not being relevant to your query/calculation (e.g. you only need the date).

Is it possible to find data from MySQL by month using JPA and java.time.LocalDate date format?

I creating an application, for that I need to find data by month using JPA and java.time.LocalDate. So, is it possible to retrieve data by month from mysql?
Thanks in advance for help.
First find start and end date of month and use between method of JPA to find data of current month.
LocalDate start = LocalDate.ofEpochDay(System.currentTimeMillis() / (24 * 60 * 60 * 1000) ).withDayOfMonth(1);
LocalDate end = LocalDate.ofEpochDay(System.currentTimeMillis() / (24 * 60 * 60 * 1000) ).plusMonths(1).withDayOfMonth(1).minusDays(1);
In Repository
List<Object> findByCreatedateGreaterThanAndCreatedateLessThan(LocalDate start,LocalDate end);
Its better to use the between keyword, it makes things allot shorter.
List<Object> findByCreatedateBetween(LocalDate start,LocalDate end);
Also if you want to use the LocalDate or LocalDateTime objects with Spring Data you should use the converter class Jsr310JpaConverters or else the documents will be stored as Blobs instead of Dates (which is bad for portability of the database). Please see this tutorial on how to implement the Converter.
https://www.mkyong.com/spring-boot/spring-boot-spring-data-jpa-java-8-date-and-time-jsr310/
tl;dr
YearMonth.now( ZoneId.of( "Pacific/Auckland" ) ) // Get current month for particular time zone.
.atDayOfMonth( 1 ) // Get the first date of that month.
.plusMonths( 1 ) // Get first of next month for Half-Open query.
Details
Assuming your column in MySQL is of DATE type…
LocalDate
The LocalDate class represents a date-only value without time-of-day and without time zone.
Time zone
A time zone is crucial in determining a date. For any given moment, the date varies around the globe by zone. For example, a few minutes after midnight in Paris France is a new day while still “yesterday” in Montréal Québec.
Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 3-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).
ZoneId z = ZoneId.of( "America/Montreal" );
LocalDate today = LocalDate.now( z );
YearMonth
The YearMonth class represents an entire month. Getting the current month requires a time zone as discussed above. Around the beginning/ending of the month, the current moment could be “next” month in Auckland New Zealand while still “previous” month in Kolkata India.
YearMonth currentMonth = YearMonth.now( z ) ;
Get the first date of the month.
LocalDate start = currentMonth.atDayOfMonth( 1 ) ;
Half-Open
Generally best to use the Half-Open [) approach to defining a span of time, where the beginning is inclusive while the ending is exclusive. So defining a month means starting with the first date of the month and running up to, but not including, the first date of the following month.
LocalDate stop = start.plusMonths( 1 ) ;
Query
Do not use the BETWEEN command in SQL as it is fully closed [], both beginning and ending being inclusive. Half-Open uses >= & < logic.
SELECT when FROM tbl
WHERE when >= start
AND when < stop
;
it's also useful
#Query("from PogWorkTime p where p.codePto = :codePto and month(p.dateApply) = :month and year(p.dateApply) = :year")
Iterable<PtoExceptWorkTime> findByCodePtoAndDateApply_MonthAndDateApply_Year(#Param("codePto") String codePto,#Param("month") int month, #Param("year") int year);

Impala: return day of the built-in function trunc()

When I use trunc(timestamp, 'D') , it always gives me the Monday of that week. Is it possible to ask the function to return other day of the week, such as Tuesday? Thanks!
You should use trunc(timestamp, 'J'). See the documentation for Day, you're using 'Starting day of the week':
trunc(timestamp, string unit)
Purpose: Strips off fields from a TIMESTAMP value.
Unit argument: The unit argument value is case-sensitive. This argument string can be one of:
SYYYY, YYYY, YEAR, SYEAR, YYY, YY, Y: Year.
Q: Quarter.
MONTH, MON, MM, RM: Month.
WW, W: Same day of the week as the first day of the month.
DDD, DD, J: Day.
DAY, DY, D: Starting day of the week. (Not necessarily the current day.)
HH, HH12, HH24: Hour. A TIMESTAMP value truncated to the hour is always represented in 24-hour notation, even for the HH12 argument string.
MI: Minute.
https://www.cloudera.com/documentation/enterprise/latest/topics/impala_datetime_functions.html
easy, just try
SELECT TRUNC(timestamp, 'D') + INTERVAL 1 DAY;

What is the precise definition of JDE's Julian Date format?

I am writing code to convert from a Gregorian date to a JDE (J.D.Edwards) Julian date.
Note: a JDE Julian date is different from the normal usage of the term Julian date.
As far as I can work out from Googling, the definition of a JDE Julian date is:
1000*(year-1900) + dayofyear
where year is the 4-digit year (e.g. 2009), and dayofyear is 1 for 1st January, and counts up all year to either 365 or 366 for 31st December (depending whether this is a leap year).
My question is this: are years before 1900 supported? If so, does the above formula still hold, or should it be this:
1000*(year-1900) - dayofyear
(note minus instead of plus.)
or something else?
Does anyone have a link to the official documentation for this date format?
The JDE Julian date consists of CYYDDD which is Century, Year, Day of year.
Century is zero for 20th e.g. 19XX and one for 21st e.g. 20XX.
The year is two digits.
So 101001 is 1 January 2001
As you can see this will not support dates before 1900.
See this Oracle page for a simple and official explanation: About the Julian Date Format
The "JDE Julian Date Converter" does return a negative value for:
1809/07/23 : -90635
As opposed to the classical Julian Date:
The Julian date for CE 1809 July 23 00:00:00.0 UT is
JD 2381986.50000
Here is a example of JD EDWARDS (AS/400 software) Julian Date, but that is not an "official" documentation and it does not seems to support dates before 1900...
Note: this "ACC: How to Convert Julian Days to Dates in Access and Back" does not support date before 1900 either... as it speaks about an "informal" Julian day, commonly used by government agencies and contractors.
The informal Julian day format used in this article is the ordinal day of a year (for example, Julian day 032 represents February 1st, or the 32nd day of the year).
Variations on informal Julian day formats include using a preceding two-digit year (for example 96032 for 2/1/96) and separating the year with a dash (for example 96-032).
Another, less popular, Julian day format uses a one digit year (for example 6-032). These additional formats do not uniquely identify the century or decade. You should carefully consider the consequences when using these formats; for example, the Julian day 00061 can be interpreted as 3/1/2000 or 3/2/1900.
Update: Sorry, JDE is probably something else. But for reference:
The JDE I know is different. From page 59 in the book
"Astronomical algorithms" (Jean Meeus, ISBN 0-943396-35-2):
"If the JD corresponds to an instant
measured in the scale of Dynamical
Time (or Ephemeris Time), the
expression Julian Ephemeris Day
(JDE) is generally used. (Not JED as
it is sometimes written. The 'E' is a
sort of index appended to 'JD')"
JD and JDE (for the same point in time) are close in value
as the difference UT and ET is on the order of minutes. E.g. ET-UT was 56.86 seconds in 1990 and -2.72 seconds in 1900.
There is also MJD (Modified Julian Day):
MJD = JD - 2400000.5
Zero point for MJD is 1858-11-17, 0h UT.
Note that JD as Julian date is a misnomer. It is
Julian day. The JD has nothing to do with the Julian
calendar. (This is in disagreement with the Wikipedia article, this
is from the author of the book mentioned above, Jean Meeus - a Belgian astronomer specializing in celestial mechanics.)
Maybe off from the question, you can convert in Excel using the following formula:
Convert Julian to Date in Excel
In Cell A2 place a Julian date, like 102324
in Cell B2 place this formula: (copy it in)
=DATE(YEAR("01/01/"&TEXT(1900+INT(A2/1000),0)),MONTH("01/01/"&TEXT(1900+INT(A2/1000),0)),DAY("01/01/"&TEXT(1900+INT(A2/1000),0)))+MOD(A2,1000)-1
The date 11/20/02 date will appear in cell B2
Convert Date to Julian in Excel
In Cell C2 copy this formula:
=(YEAR(B2)-2000+100)*1000+B2-DATE(YEAR(B2),"01","01")+1
This will convert B2 back to 102324
Save the below source code in a source member called JDEDATES. Use the runsqlstm on the first line to create the functions. You can then do things like
select jde2date(A1UPMJ), f.* from f00095 f
and see a real date.
Source:
--RUNSQLSTM SRCFILE(qtxtsrc) SRCMBR(JDEDATES) COMMIT(*NONE) NAMING(*SQL)
-- jde 2 date
create function QGPL/jde2date ( d decimal(7,0))
returns date
language sql
deterministic
contains sql
SET OPTION DATFMT=*ISO
BEGIN
if d=0 then return null;
else
return date(digits(decimal(d+1900000,7,0)));
end if;
end; -- date 2 jde
create function QGPL/date2jde ( d date)
returns decimal(7,0)
language sql
deterministic
contains sql
SET OPTION DATFMT=*ISO
BEGIN
if d is null then return 0;
else
return (YEAR(D)-1900)*1000+DAYOFYEAR(D);
end if;
end ;
Several years late to the party, but for other folks like me that find yourselves working with legacy systems like this, I hope some of my java snippets can help. I'm leveraging the fact that you can convert this CYYDDD format into yyyyDDD format and parse based on that.
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Calendar;
import java.util.SimpleDateFormat;
String jdeJulianDate = "099365"; //Testing with December 31, 1999
// Compile what the year number is
int centIndex = Integer.parseInt(jdeJulianDate.substring(0,1));
int yearIndex = Integer.parseInt(jdeJulianDate.substring(1,3));
int yearNumber = 1900 + (100 * centIndex) + yearIndex;
// Put the year number together with date ordinal to get yyyyDDD format
String fullDate = String.valueOf(yearNumber) + jdeJulianDate.substring(3,6);
// Date parsing, so need to wrap in try/catch block
try {
Date dt = new SimpleDateFormat("yyyyDDD").parse(fullDate);
// Validate it parses to a date in the same year...
Calendar cal = new GregorianCalendar();
cal.setTime(dt);
if (cal.get(Calendar.YEAR) != yearNumber) {
// Cases happen where things like 121366 (should be invalid) get parsed, yielding 2022-01-01.
// Throw exception or what-not here.
}
}
catch (Exception e) {
// Date parsing error handling here
}
A sample of VBA code to convert back and forth between JDE Julian Date and Gregorian:
Public Const Epoch = 1900
Public Const JDateMultiplier = 1000
Public Const FirstJan = "01/01/"
Public Function Julian2Date(ByVal vDate As Long) As Date
Dim Year As Long
Dim Days As Long
Dim SeedDate As Date
' Day Number
Days = vDate - (Int(vDate / JDateMultiplier) * JDateMultiplier) - 1
' Calendar Year
Year = ((vDate - Days) / JDateMultiplier) + Epoch
' First Day of Calendar Year
SeedDate = CDate(FirstJan + CStr(Year))
' Add Number of Days to First Day in Calendar Year
Julian2Date = DateAdd("d", Days, SeedDate)
End Function
Public Function Date2Julian(ByVal vDate As Date) As Long
Dim JYear As String
Dim BeginDate As Date
Dim JDays As Long
' Calendar Year
JYear = Format(Year(vDate), "0000")
' First Day of Calendar Year
BeginDate = CDate(FirstJan + JYear)
' Day Number
JDays = DateDiff("d", BeginDate, vDate) + 1
' Add Number of Days to Year Number
Date2Julian = ((CLng(JYear) - Epoch) * JDateMultiplier) + JDays
End Function
I have tried to make it as clear and simple as possible, and to this end I have intentionally left out any error trapping. However, you should be able to add the code to a VBA module and call them directly from your own code.
I also include some useful snippets of T-SQL:
Todays Date as JDE Julian Date:
(datepart(yy,getdate())-1900) * 1000 + datepart(dy, getdate())
Convert JDE Julian Date to Gregorian (DD/MM/YYYY), replace XXXXXX with the column name containing the JDE Julian Date:
convert (varchar, dateadd (day,convert (int, right(XXXXXX,3)) - 1, convert (datetime, ('1/1/' + convert ( varchar, (cast(left(right(XXXXXX+1000000,6),3) as varchar) + 1900))))),103)
If you require a different Gregorian format, replace the 103 value (right at the end) with the applicable value found here: https://msdn.microsoft.com/en-us/library/ms187928.aspx
I have an easy way for C using time now and epoch 1970, 01, 01 midnight if anybody is interested.
But this is for Julian Day Numbers which is not the same as JDE but they are similar in respect to using math to compute days and I'm sure this idea could be adapted for JDE. Sometimes people just confuse the two like I do. Sorry. But still this is an example of using a time reference which should always be done and since most computers use this it would be just as easy for us not to get too bogged down in dates and just use days before or after this epoch.
Since JDE is now owned by Oracle, they also now support Julian_Day. see:
https://docs.oracle.com/javase/8/docs/api/java/time/temporal/JulianFields.html
#include <stdio.h>
#include <time.h>
#define EPOCH (double) 2440587.5 /* Julian Day number for Jan. 01, 1970 midnight */
int main ()
{
double days = time(0)/86400.0;
printf ("%f days since January 1, 1970\n", days);
printf ("%f\n", days + EPOCH);
return 0;
}
Wow, there's a lot of complicated code in some of these answers just to convert to and from JDE julian dates. There are simple ways in Excel and VBA to get there.
FROM JULIAN
Excel (assuming julian date is in A1):
=DATE(1900+LEFT(A1,LEN(A1)-3),1,RIGHT(A1,3))
VBA (from julian date, j, stored as String):
d = DateSerial(1900 + Left$(j, Len(j) - 3), 1, Right$(j, 3))
VBA (from julian date, j, stored as Long):
d = DateSerial(1900 + Left$(j, Len(CStr(j)) - 3), 1, Right$(j, 3))
TO JULIAN
Excel (assuming date is in A1):
=(YEAR(A1)-1900)*1000+A1-DATE(YEAR(A1),1,0)
VBA (to a Long, j):
j = (Year(d) - 1900) * 1000 + DatePart("y", d)