fasti 0.2.0

Dates, calendars, business-day conventions and day-count fractions for financial code. Native Rust, no_std, float-free; designed after QuantLib's ql/time.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165

//! US Federal Reserve Bankwire System calendar — `QuantLib`'s
//! `UnitedStates::FederalReserve`.

use crate::{
    Calendar, FixedDate, LastWeekday, Month, NthWeekday, Ordinal, Rule, Weekday, Weekend,
    WeekendShift, Year, YearRange,
};

/// The Federal Reserve Bankwire System calendar — a port of
/// `QuantLib`'s `UnitedStates::FederalReserve` market variant.
///
/// Same holiday set as [`SETTLEMENT`](super::SETTLEMENT), but modern
/// weekend shifts are Sunday-forward only; the legacy pre-1971 variants
/// keep the full SatBack/SunForward shift, matching `QuantLib`.
///
/// | Holiday | Rule |
/// |---|---|
/// | New Year's Day | Jan 1 + SunForward |
/// | Martin Luther King Jr. Day | 3rd Mon of January *[since 1983]* |
/// | Washington's Birthday (pre-1971) | Feb 22 + SatBack/SunForward *[through 1970]* |
/// | Washington's Birthday | 3rd Mon of February *[since 1971]* |
/// | Memorial Day (pre-1971) | May 30 + SatBack/SunForward *[through 1970]* |
/// | Memorial Day | Last Mon of May *[since 1971]* |
/// | Juneteenth | Jun 19 + SunForward *[since 2022]* |
/// | Independence Day | Jul 4 + SunForward |
/// | Labor Day | 1st Mon of September |
/// | Columbus Day | 2nd Mon of October *[since 1971]* |
/// | Veterans Day | Nov 11 + SunForward *[through 1970]* |
/// | Veterans Day (Uniform Monday) | 4th Mon of October *[1971–1977]* |
/// | Veterans Day | Nov 11 + SunForward *[from 1978]* |
/// | Thanksgiving | 4th Thu of November |
/// | Christmas | Dec 25 + SunForward |
pub const FEDERAL_RESERVE: Calendar<'static> = Calendar {
    name: "Federal Reserve Bankwire System",
    weekend: Weekend::SAT_SUN,
    rules: &[
        // New Year's Day — SunForward.
        Rule::Fixed(FixedDate::new(Month::Jan, 1).shift(WeekendShift::SunForward)),
        // MLK — 3rd Monday of January, since 1983.
        Rule::NthWeekday(
            NthWeekday::new(Ordinal::Third, Weekday::Mon, Month::Jan)
                .from_year(Year::literal(1983)),
        ),
        // Washington's Birthday (pre-1971): Feb 22 with full weekend shift.
        Rule::Fixed(
            FixedDate::new(Month::Feb, 22)
                .shift(WeekendShift::SatBackSunForward)
                .years(YearRange::literal_through(1970)),
        ),
        // Washington's Birthday (1971+): 3rd Monday of February.
        Rule::NthWeekday(
            NthWeekday::new(Ordinal::Third, Weekday::Mon, Month::Feb)
                .from_year(Year::literal(1971)),
        ),
        // Memorial Day (pre-1971): May 30 with full weekend shift.
        Rule::Fixed(
            FixedDate::new(Month::May, 30)
                .shift(WeekendShift::SatBackSunForward)
                .years(YearRange::literal_through(1970)),
        ),
        // Memorial Day (1971+): Last Monday of May.
        Rule::LastWeekday(
            LastWeekday::new(Weekday::Mon, Month::May).from_year(Year::literal(1971)),
        ),
        // Juneteenth (2022+): Jun 19 SunForward.
        Rule::Fixed(
            FixedDate::new(Month::Jun, 19)
                .shift(WeekendShift::SunForward)
                .from_year(Year::literal(2022)),
        ),
        // Independence Day — SunForward.
        Rule::Fixed(FixedDate::new(Month::Jul, 4).shift(WeekendShift::SunForward)),
        // Labor Day — 1st Monday of September.
        Rule::NthWeekday(NthWeekday::new(Ordinal::First, Weekday::Mon, Month::Sep)),
        // Columbus Day (1971+): 2nd Monday of October.
        Rule::NthWeekday(
            NthWeekday::new(Ordinal::Second, Weekday::Mon, Month::Oct)
                .from_year(Year::literal(1971)),
        ),
        // Veterans Day (pre-1971): Nov 11 SunForward.
        Rule::Fixed(
            FixedDate::new(Month::Nov, 11)
                .shift(WeekendShift::SunForward)
                .years(YearRange::literal_through(1970)),
        ),
        // Veterans Day (1971-1977): 4th Monday of October.
        Rule::NthWeekday(
            NthWeekday::new(Ordinal::Fourth, Weekday::Mon, Month::Oct)
                .years(YearRange::literal_between(1971, 1977)),
        ),
        // Veterans Day (1978+): Nov 11 SunForward.
        Rule::Fixed(
            FixedDate::new(Month::Nov, 11)
                .shift(WeekendShift::SunForward)
                .from_year(Year::literal(1978)),
        ),
        // Thanksgiving — 4th Thursday of November.
        Rule::NthWeekday(NthWeekday::new(Ordinal::Fourth, Weekday::Thu, Month::Nov)),
        // Christmas — Dec 25 SunForward.
        Rule::Fixed(FixedDate::new(Month::Dec, 25).shift(WeekendShift::SunForward)),
    ],
};

#[cfg(test)]
#[allow(clippy::unwrap_used, clippy::expect_used)]
mod tests {
    use super::*;
    use crate::Date;

    fn ymd(y: u16, m: Month, d: u8) -> Date {
        Date::from_ymd(y, m, d).unwrap()
    }

    /// All 11 Federal Reserve holidays for 2024 (same set as Settlement).
    #[test]
    fn federal_reserve_holidays_2024() {
        assert!(FEDERAL_RESERVE.is_holiday(ymd(2024, Month::Jan, 1)));
        assert!(FEDERAL_RESERVE.is_holiday(ymd(2024, Month::Jan, 15)));
        assert!(FEDERAL_RESERVE.is_holiday(ymd(2024, Month::Feb, 19)));
        assert!(FEDERAL_RESERVE.is_holiday(ymd(2024, Month::May, 27)));
        assert!(FEDERAL_RESERVE.is_holiday(ymd(2024, Month::Jun, 19)));
        assert!(FEDERAL_RESERVE.is_holiday(ymd(2024, Month::Jul, 4)));
        assert!(FEDERAL_RESERVE.is_holiday(ymd(2024, Month::Sep, 2)));
        assert!(FEDERAL_RESERVE.is_holiday(ymd(2024, Month::Oct, 14)));
        assert!(FEDERAL_RESERVE.is_holiday(ymd(2024, Month::Nov, 11)));
        assert!(FEDERAL_RESERVE.is_holiday(ymd(2024, Month::Nov, 28)));
        assert!(FEDERAL_RESERVE.is_holiday(ymd(2024, Month::Dec, 25)));
    }

    /// Key diff vs Settlement: no Friday observance for Saturday holidays.
    #[test]
    fn federal_reserve_no_saturday_back_shift() {
        // Jul 4 2026 (Sat): Settlement observes Fri Jul 3; Fed does not.
        assert!(!FEDERAL_RESERVE.is_holiday(ymd(2026, Month::Jul, 3)));
        // Jan 1 2022 (Sat): Settlement observes Fri Dec 31 2021; Fed does not.
        assert!(!FEDERAL_RESERVE.is_holiday(ymd(2021, Month::Dec, 31)));
    }

    /// Sunday→Monday shifts do apply under Fed Reserve.
    #[test]
    fn federal_reserve_sunday_forward() {
        // Christmas 2022 (Sun) → observed Mon Dec 26.
        assert!(FEDERAL_RESERVE.is_holiday(ymd(2022, Month::Dec, 26)));
        // Jul 4 2021 (Sun) → observed Mon Jul 5.
        assert!(FEDERAL_RESERVE.is_holiday(ymd(2021, Month::Jul, 5)));
    }

    /// Pre-1971 Washington's Birthday keeps the full SatBack/SunForward shift.
    #[test]
    fn federal_reserve_legacy_washington_uses_sat_back() {
        assert!(FEDERAL_RESERVE.is_holiday(ymd(1970, Month::Feb, 23))); // observed
        // The natural Sunday stays a holiday; the Monday is its substitute.
        assert!(FEDERAL_RESERVE.is_holiday(ymd(1970, Month::Feb, 22)));
        // 1969 Feb 22 (Sat) → observed Friday Feb 21 under the legacy rule.
        assert!(FEDERAL_RESERVE.is_holiday(ymd(1969, Month::Feb, 21)));
    }

    /// Veterans Day 1971-1977 Uniform Monday variant applies identically.
    #[test]
    fn federal_reserve_veterans_day_uniform_monday() {
        assert!(FEDERAL_RESERVE.is_holiday(ymd(1971, Month::Oct, 25)));
        assert!(FEDERAL_RESERVE.is_holiday(ymd(1977, Month::Oct, 24)));
        assert!(!FEDERAL_RESERVE.is_holiday(ymd(1978, Month::Oct, 23)));
    }
}