Dates, times, and currency

NeoObjectPascal ships four built-in types for dealing with the real world: Date, Time, DateTime, and Currency. All of them are always available — just like Integer, you don't need any uses to work with them.

• Date — a calendar date in ISO format yyyy-MM-dd (backed by java.time.LocalDate).
• Time — a time of day HH:mm:ss (java.time.LocalTime).
• DateTime — combined date and time (java.time.LocalDateTime).
• Currency — exact decimal monetary values (java.math.BigDecimal).

In addition, Double and Float are aliases of Real (64-bit floating point): all three words name exactly the same type, so pick whichever reads more clearly in your code.

Why Currency and not Real for money?

Real (floating point) suffers from the classic error where 0.1 + 0.2 doesn't yield exactly 0.3. Currency is exact decimal: 0.1 + 0.2 is precisely 0.3. Use Currency for money and Real/Double for scientific or general-purpose calculations.

The date and time types

Creating dates and times

The creation functions come in two groups: those that capture the current instant and those that build a value from numbers. None of them require uses.

var hoje: Date;
var agora: DateTime;
var abertura: Time;
var natal: Date;

begin
    hoje := today();            // today's date
    agora := now();             // current date and time
    abertura := currentTime();  // the current time

    natal := date(2026, 12, 25);
    WriteLn(natal);             // WriteLn prints dates in ISO
end.

Saída

 2026-12-25 

You build each type with its dedicated function: date(year, month, day), time(hour, min, sec), and dateTime(year, month, day, hour, min, sec). To start from text, use the parse functions:

var d: Date;
var t: Time;
var dt: DateTime;

begin
    d := parseDate("2026-01-15");
    t := parseTime("10:30");
    dt := parseDateTime("2026-01-15 10:30:00");
    WriteLn(d);
    WriteLn(t);
end.

Saída

 2026-01-15 10:30:00 

Automatic coercion from String

When you assign a String in ISO format to a Date, Time, or DateTime variable, the value is converted automatically — there's no need to call parse:

var feriado: Date;
feriado := "2026-12-25";   // String becomes Date

Components

Extract parts of any date or time with direct functions. dayOfWeek returns 1 for Monday through 7 for Sunday.

var dt: DateTime;

begin
    dt := dateTime(2026, 7, 18, 14, 30, 0);
    WriteLn("Year: ", year(dt));
    WriteLn("Month: ", month(dt));
    WriteLn("Day: ", day(dt));
    WriteLn("Hour: ", hour(dt));
    WriteLn("Minute: ", minute(dt));
    WriteLn("Day of week (1=Monday): ", dayOfWeek(dt));
end.

Saída

 Ano: 2026 Mês: 7 Dia: 18 Hora: 14 Minuto: 30 Dia da semana (1=segunda): 6 

Comparison

The <, >, <=, >=, =, and <> operators work directly on Date, Time, and DateTime — one date is "less than" another when it comes earlier.

var vencimento: Date;
var hoje: Date;

begin
    vencimento := date(2026, 7, 10);
    hoje := date(2026, 7, 18);

    if hoje > vencimento then
        WriteLn("Deadline passed!")
    else
        WriteLn("Still within the deadline");
end.

Saída

 Prazo vencido! 

Arithmetic

Add or subtract intervals with addDays, addMonths, addYears, addHours, and addMinutes (use negative values to go back in time). To measure the distance between two points, use daysBetween and hoursBetween.

var inicio: Date;

begin
    inicio := date(2026, 7, 18);
    WriteLn("30 days from now: ", addDays(inicio, 30));
    WriteLn("Next month: ", addMonths(inicio, 1));
    WriteLn("Days until year-end: ", daysBetween(inicio, date(2026, 12, 31)));
end.

Saída

 Daqui a 30 dias: 2026-08-17 No mês que vem: 2026-08-18 Dias até o fim do ano: 166 

Formatting

format(value, pattern) returns a String in the format you ask for, using the same java.time patterns (dd, MM, yyyy, HH, mm, ss). This example combines everything: age in days, arithmetic, and formatting — in the spirit of examples/54.

var nascimento: Date;
var referencia: Date;

begin
    nascimento := date(1990, 5, 20);
    referencia := date(2026, 7, 18);

    WriteLn("Birth: ", format(nascimento, "dd/MM/yyyy"));
    WriteLn("Age in days: ", daysBetween(nascimento, referencia));
    WriteLn("30 days from now: ", format(addDays(referencia, 30), "dd/MM/yyyy"));
    WriteLn("Day of week (1=Monday): ", dayOfWeek(referencia));
end.

Saída

 Nascimento: 20/05/1990 Idade em dias: 13208 Daqui a 30 dias: 17/08/2026 Dia da semana (1=segunda): 6 

Exact money with Currency

Currency holds monetary values without any floating-point error. Create a value with currency(...), from a number or a string.

Exact arithmetic

The +, -, *, and / operators are exact on Currency. The classic case that fails with Real works perfectly here:

var a: Currency;
var b: Currency;

begin
    a := currency(0.1);
    b := currency(0.2);
    WriteLn(a + b);   // exact, no floating-point error
end.

Saída

 0.3 

Comparison holds too: <, >, <=, >=, =, and <> work on Currency.

Formatting and rounding

formatCurrency(value, symbol) returns a String in the Brazilian style — a dot as the thousands separator and a comma as the decimal. roundCurrency(value, places) rounds to the desired number of places.

var preco: Currency;

begin
    preco := currency(1234.56);
    WriteLn(formatCurrency(preco, "R$"));
end.

Saída

 R$ 1.234,56 

Example: tax calculation

A 2% tax on an amount, in the spirit of the ITBI calculation in examples/55. Since everything is Currency, the result is exact down to the cent:

var baseCalculo: Currency;
var aliquota: Real;
var imposto: Currency;

begin
    baseCalculo := currency(520000.00);
    aliquota := 0.02;   // 2%
    imposto := baseCalculo * currency(aliquota);

    WriteLn("Tax base:     ", formatCurrency(baseCalculo, "R$"));
    WriteLn("Rate:         2%");
    WriteLn("Tax due:      ", formatCurrency(imposto, "R$"));
end.

Saída

 Base de cálculo: R$ 520.000,00 Alíquota: 2% Imposto devido: R$ 10.400,00 

Choose the right type

Use Currency for any monetary value — prices, taxes, balances — where the cents have to add up exactly. Reserve Real/Double for scientific math and general-purpose calculations, where a small floating-point imprecision is acceptable.

Default printing

WriteLn prints dates in ISO (2026-12-25) and Currency values as a plain decimal (10400.00). For output in your country's format, always use format and formatCurrency.

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