From cf8766df83f03152026c2301ff99eb7121d702ba Mon Sep 17 00:00:00 2001
From: xuri <xuri.me@gmail.com>
Date: Sat, 16 Oct 2021 16:05:50 +0800
Subject: [PATCH] ref #65, new formula function: TIME

---
 calc.go      | 25 +++++++++++++++++++++++++
 calc_test.go |  8 ++++++++
 cell_test.go | 10 +++++-----
 3 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/calc.go b/calc.go
index a4ecb66..b8cb645 100644
--- a/calc.go
+++ b/calc.go
@@ -489,6 +489,7 @@ type formulaFuncs struct {
 //    T
 //    TAN
 //    TANH
+//    TIME
 //    TODAY
 //    TRANSPOSE
 //    TRIM
@@ -6848,6 +6849,30 @@ func (fn *formulaFuncs) NOW(argsList *list.List) formulaArg {
 	return newNumberFormulaArg(25569.0 + float64(now.Unix()+int64(offset))/86400)
 }
 
+// TIME function accepts three integer arguments representing hours, minutes
+// and seconds, and returns an Excel time. I.e. the function returns the
+// decimal value that represents the time in Excel. The syntax of the Time
+// function is:
+//
+//    TIME(hour,minute,second)
+//
+func (fn *formulaFuncs) TIME(argsList *list.List) formulaArg {
+	if argsList.Len() != 3 {
+		return newErrorFormulaArg(formulaErrorVALUE, "TIME requires 3 number arguments")
+	}
+	h := argsList.Front().Value.(formulaArg).ToNumber()
+	m := argsList.Front().Next().Value.(formulaArg).ToNumber()
+	s := argsList.Back().Value.(formulaArg).ToNumber()
+	if h.Type != ArgNumber || m.Type != ArgNumber || s.Type != ArgNumber {
+		return newErrorFormulaArg(formulaErrorVALUE, "TIME requires 3 number arguments")
+	}
+	t := (h.Number*3600 + m.Number*60 + s.Number) / 86400
+	if t < 0 {
+		return newErrorFormulaArg(formulaErrorNUM, formulaErrorNUM)
+	}
+	return newNumberFormulaArg(t)
+}
+
 // TODAY function returns the current date. The function has no arguments and
 // therefore. The syntax of the function is:
 //
diff --git a/calc_test.go b/calc_test.go
index da95790..89f54ea 100644
--- a/calc_test.go
+++ b/calc_test.go
@@ -1016,6 +1016,10 @@ func TestCalcCellValue(t *testing.T) {
 		"=YEARFRAC(\"02/29/2000\", \"01/29/2001\",1)": "0.915300546448087",
 		"=YEARFRAC(\"02/29/2000\", \"03/29/2000\",1)": "0.0792349726775956",
 		"=YEARFRAC(\"01/31/2000\", \"03/29/2000\",4)": "0.163888888888889",
+		// TIME
+		"=TIME(5,44,32)":             "0.239259259259259",
+		"=TIME(\"5\",\"44\",\"32\")": "0.239259259259259",
+		"=TIME(0,0,73)":              "0.000844907407407407",
 		// Text Functions
 		// CHAR
 		"=CHAR(65)": "A",
@@ -2093,6 +2097,10 @@ func TestCalcCellValue(t *testing.T) {
 		"=YEARFRAC(42005,42094,\"\")": "strconv.ParseFloat: parsing \"\": invalid syntax",
 		// NOW
 		"=NOW(A1)": "NOW accepts no arguments",
+		// TIME
+		"=TIME()":         "TIME requires 3 number arguments",
+		"=TIME(\"\",0,0)": "TIME requires 3 number arguments",
+		"=TIME(0,0,-1)":   "#NUM!",
 		// TODAY
 		"=TODAY(A1)": "TODAY accepts no arguments",
 		// Text Functions
diff --git a/cell_test.go b/cell_test.go
index 0395ef4..f699c05 100644
--- a/cell_test.go
+++ b/cell_test.go
@@ -268,11 +268,11 @@ func TestGetCellValue(t *testing.T) {
     <c r="T1"><v>68.900000000000006</v></c>
     <c r="U1"><v>8.8880000000000001E-2</v></c>
     <c r="V1"><v>4.0000000000000003E-5</v></c>
-	<c r="W1"><v>2422.3000000000002</v></c>
-	<c r="X1"><v>1101.5999999999999</v></c>
-	<c r="Y1"><v>275.39999999999998</v></c>
-	<c r="Z1"><v>68.900000000000006</v></c>
-	<c r="AA1"><v>1.1000000000000001</v></c>
+    <c r="W1"><v>2422.3000000000002</v></c>
+    <c r="X1"><v>1101.5999999999999</v></c>
+    <c r="Y1"><v>275.39999999999998</v></c>
+    <c r="Z1"><v>68.900000000000006</v></c>
+    <c r="AA1"><v>1.1000000000000001</v></c>
 </row>`)))
 	f.checked = nil
 	rows, err = f.GetRows("Sheet1")