Date, number & money functions

This group contains 11 functions covering both the wording and the arithmetic of Vietnamese construction paperwork: dates and times written out for acceptance records (Vietnamese, English or bilingual), lunar/solar calendar conversion, amounts spelled out in words, automatic quantity explanations built from cell formulas, linear interpolation and steel weight.

The examples below use a semicolon ; to separate arguments (Excel running on a Vietnamese regional format). If your Excel uses the English (US) format, type a comma , instead of ;.

Quick reference:

Function	Purpose
dvdLDate	Write a date as the sentence used in official records.
dvdLTime	Write hours and minutes in words.
dvdLTimeDate	Write time and date together in words.
dvdLunarToSolar	Convert a lunar date into a solar date.
dvdSolarToLunar	Convert a solar date into a lunar date.
dvdVnd	Spell a Vietnamese dong amount out in words.
dvdUsd	Spell a dollar amount out in English words.
dvdExplain	Explain a formula as result = expression.
dvdExplainE	Explain a formula as expression = result.
dvdNoiSuy	One-dimensional linear interpolation.
dvdSteelWeight	Steel weight from bar diameter and quantity.

dvdLDate

Writes a date cell as the sentence used in official records, optionally prefixed with a place name.

Syntax:

=dvdLDate(shortDate; [Location]; [Language])

Parameter	Required	Description
shortDate	Yes	Cell holding a date value.
Location	No	Place name added in front of the sentence.
Language	No	0 = Vietnamese (default), 1 = English, 2 = bilingual.

Example:

=dvdLDate(D6; "Hà Nội"; 0)
// → "Hà Nội, ngày 22 tháng 8 năm 2026"

=dvdLDate(D6; ; 2)
// → "ngày/date 22 tháng/month 8 năm/year 2026"

Notes

• Passing an empty string "" as Location produces a dotted line to fill in by hand: ...................., ngày 22 tháng 8 năm 2026.
• An empty or zero date produces the blank template ngày….......tháng….......năm…......, handy for forms that are signed later.
• The day is always shown with two digits; January and February are shown as 01 and 02.

dvdLTime

Writes a time value as hours and minutes in words.

Syntax:

=dvdLTime(shortTime; [Language])

Parameter	Required	Description
shortTime	Yes	Time value of type Date.
Language	No	0 = Vietnamese (default), 1 = English, 2 = bilingual.

Example:

=dvdLTime(E6; 0)
// → "08 giờ 30 phút"

=dvdLTime(E6; 2)
// → "08 giờ/hours 30 phút/minutes"

Notes

• An empty value produces the blank template ….......giờ….......phút for forms filled in by hand.

dvdLTimeDate

Writes hours, minutes, day, month and year as one sentence — the opening line of an acceptance record.

Syntax:

=dvdLTimeDate(shortTime; shortDate; [Language])

Parameter	Required	Description
shortTime	Yes	Time value of type Date.
shortDate	Yes	Date value of type Date.
Language	No	0 = Vietnamese (default), 1 = English, 2 = bilingual.

Example:

=dvdLTimeDate(E6; D6; 0)
// → "08 giờ 30 phút, ngày 22 tháng 8 năm 2026"

dvdLunarToSolar

Converts a lunar date into the matching solar date.

Syntax:

=dvdLunarToSolar(shortDateLunar)

Parameter	Required	Description
shortDateLunar	Yes	Lunar date, entered as a date value.

Example:

=dvdLunarToSolar(DATE(2026;1;1))
// → 17/02/2026 (first day of Tết — the anchor for the holiday break in a programme)

Notes

• The result is a date value: format the cell as Date to display it correctly.
• A lunar date that does not exist returns #VALUE!.
• The conversion uses Vietnam time (GMT+7).

dvdSolarToLunar

Converts a solar date into the matching lunar date.

Syntax:

=dvdSolarToLunar(shortDateSolar)

Parameter	Required	Description
shortDateSolar	Yes	Solar date, entered as a date value.

Example:

=dvdSolarToLunar(DATE(2026;8;22))
// → "10/07/2026 AL"

Notes

• The result is text ending in AL; a leap month is flagged in brackets, for example (6 N).
• The conversion uses Vietnam time (GMT+7).

dvdVnd

Spells a Vietnamese dong amount out in words for the "in words" line of a payment certificate or contract.

Syntax:

=dvdVnd(Number; [match_mode])

Parameter	Required	Description
Number	Yes	Cell holding the amount, or the amount typed directly.
match_mode	No	0 = words only (default), 1 = prefix the result with Bằng chữ: .

Example:

=dvdVnd(125000000)
// → "Một trăm hai mươi lăm triệu đồng."

=dvdVnd(F42; 1)
// → "Bằng chữ: Một triệu, hai trăm năm mươi nghìn đồng."

Notes

• The amount is rounded to whole dong before being spelled out; negative amounts are prefixed with "âm".
• An empty cell or a non-numeric value returns an empty string.

dvdUsd

Spells a dollar amount out in English words, for bilingual contracts and payment documents.

Syntax:

=dvdUsd(Number)

Parameter	Required	Description
Number	Yes	Cell holding the amount, or the amount typed directly.

Example:

=dvdUsd(5000)
// → "Five thousand dollars only"

=dvdUsd(1250.5)
// → "One thousand two hundred fifty dollars and fifty cents"

Notes

• Zero returns None; negative amounts are prefixed with Minus.

dvdExplain

Builds a quantity explanation for the cells of a range in the form result = expression, with every cell reference in the formula replaced by its actual value.

Syntax:

=dvdExplain(RangeToExplain; [HeaderRange]; [OptionValue]; [DecimalPlaces])

Parameter	Required	Description
RangeToExplain	Yes	Range of cells to explain.
HeaderRange	No	Header range; the matching header is written in front of each line.
OptionValue	No	1 = explain every cell (default), 0 = only cells that contain a formula.
DecimalPlaces	No	Number of decimals in the result; -1 keeps the original formatting.

Example:

=dvdExplain(F6; ; 0; 2)
// → "2.40=3*0.8" (F6 holds the formula =D6*E6 with D6 = 3 and E6 = 0.8)

=dvdExplain(F6:F20; $D$5:$F$5; 0; 2)
// → one line per formula cell, each prefixed with its column header

Notes

• SUM(...) is expanded into a chain of additions and PRODUCT(...) into a chain of multiplications of the individual cells.
• Multiple cells produce multiple lines separated by line breaks: turn on Wrap Text on the formula cell to read them all.
• The first argument must be a real cell or range reference on the sheet; passing an intermediate value returns an empty result.

dvdExplainE

Same as dvdExplain but written the other way round, expression = result, which suits the quantity statements of as-built documentation.

Syntax:

=dvdExplainE(RangeToExplain; [HeaderRange]; [OptionValue]; [DecimalPlaces])

Parameter	Required	Description
RangeToExplain	Yes	Range of cells to explain.
HeaderRange	No	Header range; the matching header is written in front of each line.
OptionValue	No	1 = explain every cell (default), 0 = only cells that contain a formula.
DecimalPlaces	No	Number of decimals in the result; -1 keeps the original formatting.

Example:

=dvdExplainE(F6; ; 0; 2)
// → "3*0.8=2.40"

=dvdExplainE(F6:F20; ; 0; 3)
// → "5+3.2+7.8=16.000" for a cell holding =SUM(...)

Notes

• Every note for dvdExplain applies here too: real references are required, results span several lines, and SUM/PRODUCT are expanded.

dvdNoiSuy

One-dimensional linear interpolation between two known points — norms, haulage factors, excavation-depth factors.

Syntax:

=dvdNoiSuy(x1; x2; y1; y2; xnew)

Parameter	Required	Description
x1	Yes	Value x1.
x2	Yes	Value x2.
y1	Yes	Value y1 matching x1.
y2	Yes	Value y2 matching x2.
xnew	Yes	Value of x to interpolate at.

Example:

=dvdNoiSuy(5; 10; 120000; 150000; 7)
// → 132000 (haulage rate at a distance of 7 km)

Notes

• When x1 equals x2 the function returns #DIV/0!.

dvdSteelWeight

Calculates steel weight from bar diameter and quantity.

Syntax:

=dvdSteelWeight(diameter; quantity)

Parameter	Required	Description
diameter	Yes	Bar diameter, in mm.
quantity	Yes	Number of bars for larger diameters, or the coil weight for small-diameter coiled steel.

Example:

=dvdSteelWeight(16; 20)
// → 369.72 (kg — 20 bars of D16, 11.7 m each)

=dvdSteelWeight(8; 250)
// → 250 (kg — D8 coiled steel supplied by weight)

Notes

• For diameters of 8 and below the function returns quantity unchanged, because coiled steel is bought by weight.
• Above diameter 8 the calculation assumes standard 11.7 m bars and a density of 7,850 kg/m³.