Business value
Fineract returns dates as [year, month, day] with a 1-based month. Eighteen places convert one to a YYYY-MM-DD string by constructing a Date and formatting it back:
toIsoDate(new Date(actDateArray[0], actDateArray[1] - 1, actDateArray[2]))
src/app/core/utils/date-formatter.ts already exports a function that does this directly:
formatArrayDate(actDateArray)
The two produce identical output for a valid array — worth confirming, since the round trip through Date is not obviously lossless, and it is:
[2026, 1, 5] → 2026-01-05 both
[2026, 12, 31] → 2026-12-31 both
[1999, 2, 28] → 1999-02-28 both
The value in fixing it is the - 1. Eighteen hand-written copies of a month-offset conversion is eighteen chances to write [1] instead of [1] - 1, and an off-by-one month in a banking application is not a cosmetic bug — it moves an activation date, a disbursement date, or a closure date by a month, and the result is a plausible date rather than an obviously broken one, so nothing downstream flags it. The helper is written once and has a test.
It is also a tidier read: formatArrayDate(dates) says what it does; toIsoDate(new Date(d[0], d[1] - 1, d[2])) makes the reader verify the arithmetic.
Reproducing it
grep -rn 'toIsoDate(new Date(.*\[0\]' src/app --include=*.ts | grep -v spec # 18
grep -rl 'formatArrayDate' src/app --include=*.ts | grep -v spec | wc -l # 15 files already use it
Describing the change
Replace the round trip with the helper:
// before
const actDateArray = clientData.activationDate as unknown as number[];
if (actDateArray) {
this.activationDate.set(toIsoDate(new Date(actDateArray[0], actDateArray[1] - 1, actDateArray[2])));
}
// after
this.activationDate.set(formatArrayDate(clientData.activationDate));Two things to be careful about — please read these before starting.
-
Only the toIsoDate(new Date(...)) sites. There are 13 further sites that do
new Date(d[0], d[1] - 1, d[2]).toLocaleDateString(). Those are not the same thing:
toLocaleDateString() formats for the browser's locale (8/7/2026), while formatArrayDate
returns ISO (2026-08-07). Converting them would silently change what users see. Leave them
alone; whether display dates should be locale-formatted is a separate question worth its own
issue.
-
formatArrayDate returns '-' for a missing or malformed value, not ''. That is right
for display, and wrong for a value bound to ion-datetime, which would try to parse '-'.
Most of the 18 sites are already inside an if (someDate) guard, so behaviour is unchanged —
but check each one, and keep the guard where it exists.
One pull request per feature directory. The sites are spread across clients, loans, products, organization and transfers.
Scope
In scope: the 18 toIsoDate(new Date(arr[0], arr[1] - 1, arr[2])) sites.
Out of scope: the 13 toLocaleDateString() display sites, and any change to formatArrayDate itself.
Getting started
- Helper:
src/app/core/utils/date-formatter.ts (read the doc comments — they explain why toIsoDate avoids toISOString()).
npm run build and npm test must pass. Several of these components have specs that assert on the formatted value, which is the check that the substitution was faithful.- If a site has no spec covering it, adding one is welcome but not required.
Business value
Fineract returns dates as
[year, month, day]with a 1-based month. Eighteen places convert one to aYYYY-MM-DDstring by constructing aDateand formatting it back:src/app/core/utils/date-formatter.tsalready exports a function that does this directly:The two produce identical output for a valid array — worth confirming, since the round trip through
Dateis not obviously lossless, and it is:The value in fixing it is the
- 1. Eighteen hand-written copies of a month-offset conversion is eighteen chances to write[1]instead of[1] - 1, and an off-by-one month in a banking application is not a cosmetic bug — it moves an activation date, a disbursement date, or a closure date by a month, and the result is a plausible date rather than an obviously broken one, so nothing downstream flags it. The helper is written once and has a test.It is also a tidier read:
formatArrayDate(dates)says what it does;toIsoDate(new Date(d[0], d[1] - 1, d[2]))makes the reader verify the arithmetic.Reproducing it
Describing the change
Replace the round trip with the helper:
Two things to be careful about — please read these before starting.
Only the
toIsoDate(new Date(...))sites. There are 13 further sites that donew Date(d[0], d[1] - 1, d[2]).toLocaleDateString(). Those are not the same thing:toLocaleDateString()formats for the browser's locale (8/7/2026), whileformatArrayDatereturns ISO (
2026-08-07). Converting them would silently change what users see. Leave themalone; whether display dates should be locale-formatted is a separate question worth its own
issue.
formatArrayDatereturns'-'for a missing or malformed value, not''. That is rightfor display, and wrong for a value bound to
ion-datetime, which would try to parse'-'.Most of the 18 sites are already inside an
if (someDate)guard, so behaviour is unchanged —but check each one, and keep the guard where it exists.
One pull request per feature directory. The sites are spread across
clients,loans,products,organizationandtransfers.Scope
In scope: the 18
toIsoDate(new Date(arr[0], arr[1] - 1, arr[2]))sites.Out of scope: the 13
toLocaleDateString()display sites, and any change toformatArrayDateitself.Getting started
src/app/core/utils/date-formatter.ts(read the doc comments — they explain whytoIsoDateavoidstoISOString()).npm run buildandnpm testmust pass. Several of these components have specs that assert on the formatted value, which is the check that the substitution was faithful.