Rdb: Ruby-Nachbau der MWC /rdb-Werkzeuge

man/gregorian.man

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+.TH gregorian "" "" "/rdb Command"
+.PC "Convert column of dates for arithmetic and format change"
+\fBgregorian  [ \-ceu ] [ \fIColumn ... \fB] < \fItableorlist\fR
+.PP
+.II "date^Gregorian"
+.II "Gregorian date"
+.II "date^convert"
+The command
+.B gregorian
+converts Julian dates in one or more
+.BR Column s
+to Gregorian date.
+When used with the command
+.BR julian ,
+you can do the following:
+.IP \fB1.\fR 0.3i
+Add days to a date.
+.IP \fB2.\fR
+Subtract days from a date.
+.IP \fB3.\fR
+Subtract two dates to find the number of days between them.
+.IP \fB4.\fR
+Change the format of a date.
+.PP
+A Gregorian date is a string that presents the date of the
+current year, month, and day; for example ``911231''.
+A Julian date, however, is the number of days since the
+beginning of the Julian calendar (January 1, 4713 BC).
+This system is used by astronomers, computer programmers, and other
+people who wish to store dates in a form that can be
+easily translated from one system of dating to another, without having
+to worry about leap years, dates of the births of religious figures, etc.
+Because Julian dates are integers,
+you can subtract one from another to find the number of days between
+two dates.
+.PP
+To perform arithmetic on dates, first use the command
+.B julian
+to convert the dates from Gregorian form to Julian.
+Then, use the command
+.B compute
+to add or subtract the dates (or add a constant to a date).
+Finally, use
+.B gregorian
+to convert the sum or the difference back to Gregorian form.
+.SH Options
+.B gregorian
+recognizes the following options:
+.IP \fB\-c\fR 0.3i
+Output
+\fIcomputer\fR
+date format, i.e., \fIYYMMDD\fR.
+.B /rdb
+uses this format by default for its Gregorian dates
+because it can be sorted and selected in correct numerical sequence.
+.IP \fB\-e\fR
+Output
+.I European
+date format, i.e., \fIDD/MM/YY\fR.
+.IP \fB\-u\fR
+Output
+.I U.S.
+date format, i.e., \fIMM/DD/YY\fR.
+.SH Example
+The first example shows how to add dates.
+Suppose we have a file called
+.BR journal ,
+as follows:
+.DM
+Date    Account Debit   Credit  Description                       
+------  ------- -----   ------  ----------------------------------
+861222  101     25000           cash from loan
+861222  211.1            25000  loan number #378-14 Bank Amerigold
+861223  150.1   10000           test equipment from Zarkoff
+861223  101               5000  cash payment
+861223  211.2             5000  note payable to Zarkoff Equipment
+861224  130     30000           inventory - parts from CCPSC
+861224  201.1            15000  accounts payable to CCPSC
+861224  101              15000  cash payment to CCPSC for parts
+.DE
+.PP
+Now, suppose that we want to add 45 days to each of the dates.
+First, see what
+.B julian
+does.
+Typing
+.DM
+	julian Date < journal
+.DE
+.PP
+prints the following on the standard output:
+.DM
+Date    Account Debit   Credit  Description                       
+------  ------- -----   ------  ----------------------------------
+1752827 101     25000           cash from loan
+1752827 211.1            25000  loan number #378-14 Bank Amerigold
+1752828 150.1   10000           test equipment from Zarkoff
+1752828 101               5000  cash payment
+1752828 211.2             5000  note payable to Zarkoff Equipment
+1752829 130     30000           inventory - parts from CCPSC
+1752829 201.1            15000  accounts payable to CCPSC
+1752829 101              15000  cash payment to CCPSC for parts
+.DE
+.PP
+The
+.B Date
+column now holds a Julian date.
+Note we gave no option because computer format is the default.
+.PP
+The next command adds 45 days to each entry in the
+.B Date
+column:
+.DM
+julian Date < journal | compute 'Date += 45' | gregorian Date
+.DE
+.PP
+This command prints the following on the standard output:
+.DM
+Date    Account Debit   Credit  Description                       
+------  ------- -----   ------  ----------------------------------
+870205  101     25000           cash from loan
+870205  211.1            25000  loan number #378-14 Bank Amerigold
+870206  150.1   10000           test equipment from Zarkoff
+870206  101               5000  cash payment
+870206  211.2             5000  note payable to Zarkoff Equipment
+870207  130     30000           inventory - parts from CCPSC
+870207  201.1            15000  accounts payable to CCPSC
+870207  101              15000  cash payment to CCPSC for parts
+.DE
+.PP
+As you can see, every date is now 45 days later than they originally were.
+.PP
+The next example converts one format of Gregorian date to another.
+To convert the
+.B Date
+column in our example table from computer format to U.S. format,
+type the following:
+.DM
+	julian Date < journal | gregorian -u Date | justify Date
+.DE
+.PP
+The result is as follows:
+.DM
+Date            Account Debit   Credit  Description                       
+--------        ------- -----   ------  ----------------------------------
+12/22/86        101     25000           cash from loan
+12/22/86        211.1            25000  loan number #378-14 Bank Amerigold
+12/23/86        150.1   10000           test equipment from Zarkoff
+12/23/86        101               5000  cash payment
+12/23/86        211.2             5000  note payable`to Zarkoff Equipment
+12/24/86        130     30000           inventory - parts from CCPSC
+12/24/86        201.1            15000  accounts payable to CCPSC
+12/24/86        101              15000  cash payment to CCPSC for parts
+.DE
+.PP
+Because the U.S. format is two characters wider than the
+computer format, we included the command
+.B justify
+in our command line to line things up.
+.SH "See Also"
+.B
+compute,
+computedate,
+julian
+.R
+.br
+COHERENT Lexicon:
+.B
+awk,
+date
+.R