v0.0.512

exerr/constructor.go

@@ -12,6 +12,8 @@ import (
 var reflectTypeStr = reflect.TypeOf("")
 
 func FromError(err error) *ExErr {
+
+	//goland:noinspection GoTypeAssertionOnErrors
 	if verr, ok := err.(*ExErr); ok {
 		// A simple ExErr
 		return verr

exerr/helper.go

@@ -86,3 +86,28 @@ func MessageMatch(e error, matcher func(string) bool) bool {
 
 	return false
 }
+
+// OriginalError returns the lowest level error, probably the original/external error that was originally wrapped
+func OriginalError(e error) error {
+	if e == nil {
+		return nil
+	}
+
+	//goland:noinspection GoTypeAssertionOnErrors
+	bmerr, ok := e.(*ExErr)
+	for !ok {
+		return e
+	}
+
+	for bmerr.OriginalError != nil {
+		bmerr = bmerr.OriginalError
+	}
+
+	if bmerr.WrappedErr != nil {
+		if werr, ok := bmerr.WrappedErr.(error); ok {
+			return werr
+		}
+	}
+
+	return bmerr
+}

ginext/responseJson.go

@@ -7,10 +7,11 @@ import (
 )
 
 type jsonHTTPResponse struct {
-	statusCode int
-	data       any
-	headers    []headerval
-	cookies    []cookieval
+	statusCode     int
+	data           any
+	headers        []headerval
+	cookies        []cookieval
+	filterOverride *string
 }
 
 func (j jsonHTTPResponse) jsonRenderer(g *gin.Context) json.GoJsonRender {
@@ -18,6 +19,9 @@ func (j jsonHTTPResponse) jsonRenderer(g *gin.Context) json.GoJsonRender {
 	if jsonfilter := g.GetString(jsonFilterKey); jsonfilter != "" {
 		f = &jsonfilter
 	}
+	if j.filterOverride != nil {
+		f = j.filterOverride
+	}
 	return json.GoJsonRender{Data: j.data, NilSafeSlices: true, NilSafeMaps: true, Filter: f}
 }
 
@@ -68,3 +72,7 @@ func (j jsonHTTPResponse) Headers() []string {
 func JSON(sc int, data any) HTTPResponse {
 	return &jsonHTTPResponse{statusCode: sc, data: data}
 }
+
+func JSONWithFilter(sc int, data any, f string) HTTPResponse {
+	return &jsonHTTPResponse{statusCode: sc, data: data, filterOverride: &f}
+}

go.mod

@@ -9,9 +9,9 @@ require (
 	github.com/rs/xid v1.6.0
 	github.com/rs/zerolog v1.33.0
 	go.mongodb.org/mongo-driver v1.16.1
-	golang.org/x/crypto v0.26.0
-	golang.org/x/sys v0.24.0
-	golang.org/x/term v0.23.0
+	golang.org/x/crypto v0.27.0
+	golang.org/x/sys v0.25.0
+	golang.org/x/term v0.24.0
 )
 
 require (
@@ -21,7 +21,7 @@ require (
 )
 
 require (
-	github.com/bytedance/sonic v1.12.1 // indirect
+	github.com/bytedance/sonic v1.12.2 // indirect
 	github.com/bytedance/sonic/loader v0.2.0 // indirect
 	github.com/chenzhuoyu/base64x v0.0.0-20230717121745-296ad89f973d // indirect
 	github.com/chenzhuoyu/iasm v0.9.1 // indirect
@@ -32,7 +32,7 @@ require (
 	github.com/gin-contrib/sse v0.1.0 // indirect
 	github.com/go-playground/locales v0.14.1 // indirect
 	github.com/go-playground/universal-translator v0.18.1 // indirect
-	github.com/go-playground/validator/v10 v10.22.0 // indirect
+	github.com/go-playground/validator/v10 v10.22.1 // indirect
 	github.com/goccy/go-json v0.10.3 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/google/uuid v1.5.0 // indirect
@@ -53,10 +53,10 @@ require (
 	github.com/xdg-go/scram v1.1.2 // indirect
 	github.com/xdg-go/stringprep v1.0.4 // indirect
 	github.com/youmark/pkcs8 v0.0.0-20240726163527-a2c0da244d78 // indirect
-	golang.org/x/arch v0.9.0 // indirect
-	golang.org/x/image v0.19.0 // indirect
-	golang.org/x/net v0.28.0 // indirect
-	golang.org/x/text v0.17.0 // indirect
+	golang.org/x/arch v0.10.0 // indirect
+	golang.org/x/image v0.20.0 // indirect
+	golang.org/x/net v0.29.0 // indirect
+	golang.org/x/text v0.18.0 // indirect
 	google.golang.org/protobuf v1.34.2 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	modernc.org/libc v1.37.6 // indirect

go.sum

@@ -28,6 +28,8 @@ github.com/bytedance/sonic v1.12.0 h1:YGPgxF9xzaCNvd/ZKdQ28yRovhfMFZQjuk6fKBzZ3l
 github.com/bytedance/sonic v1.12.0/go.mod h1:B8Gt/XvtZ3Fqj+iSKMypzymZxw/FVwgIGKzMzT9r/rk=
 github.com/bytedance/sonic v1.12.1 h1:jWl5Qz1fy7X1ioY74WqO0KjAMtAGQs4sYnjiEBiyX24=
 github.com/bytedance/sonic v1.12.1/go.mod h1:B8Gt/XvtZ3Fqj+iSKMypzymZxw/FVwgIGKzMzT9r/rk=
+github.com/bytedance/sonic v1.12.2 h1:oaMFuRTpMHYLpCntGca65YWt5ny+wAceDERTkT2L9lg=
+github.com/bytedance/sonic v1.12.2/go.mod h1:B8Gt/XvtZ3Fqj+iSKMypzymZxw/FVwgIGKzMzT9r/rk=
 github.com/bytedance/sonic/loader v0.1.0/go.mod h1:UmRT+IRTGKz/DAkzcEGzyVqQFJ7H9BqwBO3pm9H/+HY=
 github.com/bytedance/sonic/loader v0.1.1 h1:c+e5Pt1k/cy5wMveRDyk2X4B9hF4g7an8N3zCYjJFNM=
 github.com/bytedance/sonic/loader v0.1.1/go.mod h1:ncP89zfokxS5LZrJxl5z0UJcsk4M4yY2JpfqGeCtNLU=
@@ -93,6 +95,8 @@ github.com/go-playground/validator/v10 v10.21.0 h1:4fZA11ovvtkdgaeev9RGWPgc1uj3H
 github.com/go-playground/validator/v10 v10.21.0/go.mod h1:dbuPbCMFw/DrkbEynArYaCwl3amGuJotoKCe95atGMM=
 github.com/go-playground/validator/v10 v10.22.0 h1:k6HsTZ0sTnROkhS//R0O+55JgM8C4Bx7ia+JlgcnOao=
 github.com/go-playground/validator/v10 v10.22.0/go.mod h1:dbuPbCMFw/DrkbEynArYaCwl3amGuJotoKCe95atGMM=
+github.com/go-playground/validator/v10 v10.22.1 h1:40JcKH+bBNGFczGuoBYgX4I6m/i27HYW8P9FDk5PbgA=
+github.com/go-playground/validator/v10 v10.22.1/go.mod h1:dbuPbCMFw/DrkbEynArYaCwl3amGuJotoKCe95atGMM=
 github.com/go-sql-driver/mysql v1.6.0 h1:BCTh4TKNUYmOmMUcQ3IipzF5prigylS7XXjEkfCHuOE=
 github.com/go-sql-driver/mysql v1.6.0/go.mod h1:DCzpHaOWr8IXmIStZouvnhqoel9Qv2LBy8hT2VhHyBg=
 github.com/go-sql-driver/mysql v1.8.1 h1:LedoTUt/eveggdHS9qUFC1EFSa8bU2+1pZjSRpvNJ1Y=
@@ -247,6 +251,8 @@ golang.org/x/arch v0.8.0 h1:3wRIsP3pM4yUptoR96otTUOXI367OS0+c9eeRi9doIc=
 golang.org/x/arch v0.8.0/go.mod h1:FEVrYAQjsQXMVJ1nsMoVVXPZg6p2JE2mx8psSWTDQys=
 golang.org/x/arch v0.9.0 h1:ub9TgUInamJ8mrZIGlBG6/4TqWeMszd4N8lNorbrr6k=
 golang.org/x/arch v0.9.0/go.mod h1:FEVrYAQjsQXMVJ1nsMoVVXPZg6p2JE2mx8psSWTDQys=
+golang.org/x/arch v0.10.0 h1:S3huipmSclq3PJMNe76NGwkBR504WFkQ5dhzWzP8ZW8=
+golang.org/x/arch v0.10.0/go.mod h1:FEVrYAQjsQXMVJ1nsMoVVXPZg6p2JE2mx8psSWTDQys=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20200302210943-78000ba7a073/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
@@ -271,6 +277,8 @@ golang.org/x/crypto v0.25.0 h1:ypSNr+bnYL2YhwoMt2zPxHFmbAN1KZs/njMG3hxUp30=
 golang.org/x/crypto v0.25.0/go.mod h1:T+wALwcMOSE0kXgUAnPAHqTLW+XHgcELELW8VaDgm/M=
 golang.org/x/crypto v0.26.0 h1:RrRspgV4mU+YwB4FYnuBoKsUapNIL5cohGAmSH3azsw=
 golang.org/x/crypto v0.26.0/go.mod h1:GY7jblb9wI+FOo5y8/S2oY4zWP07AkOJ4+jxCqdqn54=
+golang.org/x/crypto v0.27.0 h1:GXm2NjJrPaiv/h1tb2UH8QfgC/hOf/+z0p6PT8o1w7A=
+golang.org/x/crypto v0.27.0/go.mod h1:1Xngt8kV6Dvbssa53Ziq6Eqn0HqbZi5Z6R0ZpwQzt70=
 golang.org/x/image v0.0.0-20190910094157-69e4b8554b2a/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8 h1:hVwzHzIUGRjiF7EcUjqNxk3NCfkPxbDKRdnNE1Rpg0U=
 golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
@@ -282,6 +290,8 @@ golang.org/x/image v0.18.0 h1:jGzIakQa/ZXI1I0Fxvaa9W7yP25TqT6cHIHn+6CqvSQ=
 golang.org/x/image v0.18.0/go.mod h1:4yyo5vMFQjVjUcVk4jEQcU9MGy/rulF5WvUILseCM2E=
 golang.org/x/image v0.19.0 h1:D9FX4QWkLfkeqaC62SonffIIuYdOk/UE2XKUBgRIBIQ=
 golang.org/x/image v0.19.0/go.mod h1:y0zrRqlQRWQ5PXaYCOMLTW2fpsxZ8Qh9I/ohnInJEys=
+golang.org/x/image v0.20.0 h1:7cVCUjQwfL18gyBJOmYvptfSHS8Fb3YUDtfLIZ7Nbpw=
+golang.org/x/image v0.20.0/go.mod h1:0a88To4CYVBAHp5FXJm8o7QbUl37Vd85ply1vyD8auM=
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
@@ -306,6 +316,8 @@ golang.org/x/net v0.27.0 h1:5K3Njcw06/l2y9vpGCSdcxWOYHOUk3dVNGDXN+FvAys=
 golang.org/x/net v0.27.0/go.mod h1:dDi0PyhWNoiUOrAS8uXv/vnScO4wnHQO4mj9fn/RytE=
 golang.org/x/net v0.28.0 h1:a9JDOJc5GMUJ0+UDqmLT86WiEy7iWyIhz8gz8E4e5hE=
 golang.org/x/net v0.28.0/go.mod h1:yqtgsTWOOnlGLG9GFRrK3++bGOUEkNBoHZc8MEDWPNg=
+golang.org/x/net v0.29.0 h1:5ORfpBpCs4HzDYoodCDBbwHzdR5UrLBZ3sOnUJmFoHo=
+golang.org/x/net v0.29.0/go.mod h1:gLkgy8jTGERgjzMic6DS9+SP0ajcu6Xu3Orq/SpETg0=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.6.0 h1:5BMeUDZ7vkXGfEr1x9B4bRcTH4lpkTkpdh0T/J+qjbQ=
@@ -343,6 +355,8 @@ golang.org/x/sys v0.23.0 h1:YfKFowiIMvtgl1UERQoTPPToxltDeZfbj4H7dVUCwmM=
 golang.org/x/sys v0.23.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.24.0 h1:Twjiwq9dn6R1fQcyiK+wQyHWfaz/BJB+YIpzU/Cv3Xg=
 golang.org/x/sys v0.24.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.25.0 h1:r+8e+loiHxRqhXVl6ML1nO3l1+oFoWbnlu2Ehimmi34=
+golang.org/x/sys v0.25.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/term v0.16.0 h1:m+B6fahuftsE9qjo0VWp2FW0mB3MTJvR0BaMQrq0pmE=
@@ -361,6 +375,8 @@ golang.org/x/term v0.22.0 h1:BbsgPEJULsl2fV/AT3v15Mjva5yXKQDyKf+TbDz7QJk=
 golang.org/x/term v0.22.0/go.mod h1:F3qCibpT5AMpCRfhfT53vVJwhLtIVHhB9XDjfFvnMI4=
 golang.org/x/term v0.23.0 h1:F6D4vR+EHoL9/sWAWgAR1H2DcHr4PareCbAaCo1RpuU=
 golang.org/x/term v0.23.0/go.mod h1:DgV24QBUrK6jhZXl+20l6UWznPlwAHm1Q1mGHtydmSk=
+golang.org/x/term v0.24.0 h1:Mh5cbb+Zk2hqqXNO7S1iTjEphVL+jb8ZWaqh/g+JWkM=
+golang.org/x/term v0.24.0/go.mod h1:lOBK/LVxemqiMij05LGJ0tzNr8xlmwBRJ81PX6wVLH8=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
@@ -375,6 +391,8 @@ golang.org/x/text v0.16.0 h1:a94ExnEXNtEwYLGJSIUxnWoxoRz/ZcCsV63ROupILh4=
 golang.org/x/text v0.16.0/go.mod h1:GhwF1Be+LQoKShO3cGOHzqOgRrGaYc9AvblQOmPVHnI=
 golang.org/x/text v0.17.0 h1:XtiM5bkSOt+ewxlOE/aE/AKEHibwj/6gvWMl9Rsh0Qc=
 golang.org/x/text v0.17.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
+golang.org/x/text v0.18.0 h1:XvMDiNzPAl0jr17s6W9lcaIhGUfUORdGCNsuLmPG224=
+golang.org/x/text v0.18.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=

goextVersion.go

@@ -1,5 +1,5 @@
 package goext
 
-const GoextVersion = "0.0.508"
+const GoextVersion = "0.0.512"
 
-const GoextVersionTimestamp = "2024-08-25T17:36:20+0200"
+const GoextVersionTimestamp = "2024-09-15T21:25:21+0200"

gojson/encode.go

@@ -788,7 +788,7 @@ FieldLoop:
 
 		if f.omitEmpty && isEmptyValue(fv) {
 			continue
-		} else if opts.filter != nil && !matchesJSONFilter(f.jsonfilter, *opts.filter) {
+		} else if !matchesJSONFilter(f.jsonfilter, opts.filter) {
 			continue
 		}
 		e.WriteByte(next)
@@ -808,16 +808,20 @@ FieldLoop:
 	}
 }
 
-func matchesJSONFilter(filter jsonfilter, value string) bool {
+func matchesJSONFilter(filter jsonfilter, value *string) bool {
 	if len(filter) == 0 {
-		return true
+		return true // no filter in struct
+	}
+
+	if value == nil || *value == "" {
+		return false // no filter set, but struct has filter, return false
 	}
 
 	if len(filter) == 1 && filter[0] == "-" {
 		return false
 	}
 
-	if filter.Contains(value) {
+	if filter.Contains(*value) {
 		return true
 	}
 

timeext/diff.go

@@ -2,6 +2,9 @@ package timeext
 
 import "time"
 
+// YearDifference calculates the difference between two timestamps in years.
+// = t1 - t2
+// returns a float value
 func YearDifference(t1 time.Time, t2 time.Time, tz *time.Location) float64 {
 
 	yDelta := float64(t1.Year() - t2.Year())
@@ -11,3 +14,31 @@ func YearDifference(t1 time.Time, t2 time.Time, tz *time.Location) float64 {
 
 	return yDelta + (processT1 - processT2)
 }
+
+// MonthDifference calculates the difference between two timestamps in months.
+// = t1 - t2
+// returns a float value
+func MonthDifference(t1 time.Time, t2 time.Time) float64 {
+
+	yDelta := float64(t1.Year() - t2.Year())
+	mDelta := float64(t1.Month() - t2.Month())
+
+	dDelta := float64(0)
+
+	t1MonthDays := DaysInMonth(t1)
+	t2MonthDays := DaysInMonth(t2)
+
+	if t2.Year() > t1.Year() || (t2.Year() == t1.Year() && t2.Month() > t1.Month()) {
+		dDelta -= 1
+		dDelta += float64(t1MonthDays-t1.Day()) / float64(t1MonthDays)
+		dDelta += float64(t2.Day()) / float64(t2MonthDays)
+	} else if t2.Year() < t1.Year() || (t2.Year() == t1.Year() && t2.Month() < t1.Month()) {
+		dDelta -= 1
+		dDelta += float64(t1.Day()) / float64(t1MonthDays)
+		dDelta += float64(t2MonthDays-t2.Day()) / float64(t2MonthDays)
+	} else {
+		dDelta += float64(t1.Day()-t2.Day()) / float64(t1MonthDays)
+	}
+
+	return yDelta*12 + mDelta + dDelta
+}

timeext/diff_test.go

@@ -81,3 +81,63 @@ func epsilonEquals(a, b float64) bool {
 	epsilon := 0.01
 	return math.Abs(a-b) < epsilon
 }
+
+func TestMonthDifferenceSameDate(t *testing.T) {
+	t1 := time.Date(2022, 1, 1, 0, 0, 0, 0, time.UTC)
+	t2 := time.Date(2022, 1, 1, 0, 0, 0, 0, time.UTC)
+	expected := 0.0
+	result := MonthDifference(t2, t1)
+	if !epsilonEquals(result, expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}
+
+func TestMonthDifferenceSameMonth(t *testing.T) {
+	t1 := time.Date(2022, 1, 1, 0, 0, 0, 0, time.UTC)
+	t2 := time.Date(2022, 1, 31, 0, 0, 0, 0, time.UTC)
+	expected := 0.967741935483871 // Approximation of 30/31 days
+	result := MonthDifference(t2, t1)
+	if !epsilonEquals(result, expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}
+
+func TestMonthDifferenceDifferentMonthsSameYear(t *testing.T) {
+	t1 := time.Date(2022, 1, 1, 0, 0, 0, 0, time.UTC)
+	t2 := time.Date(2022, 3, 1, 0, 0, 0, 0, time.UTC)
+	expected := 2.0
+	result := MonthDifference(t2, t1)
+	if !epsilonEquals(result, expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}
+
+func TestMonthDifferenceDifferentYears(t *testing.T) {
+	t1 := time.Date(2021, 12, 1, 0, 0, 0, 0, time.UTC)
+	t2 := time.Date(2022, 2, 1, 0, 0, 0, 0, time.UTC)
+	expected := 2.0
+	result := MonthDifference(t2, t1)
+	if !epsilonEquals(result, expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}
+
+func TestMonthDifferenceT1BeforeT2(t *testing.T) {
+	t1 := time.Date(2022, 1, 1, 0, 0, 0, 0, time.UTC)
+	t2 := time.Date(2022, 6, 1, 0, 0, 0, 0, time.UTC)
+	expected := 5.0
+	result := MonthDifference(t2, t1)
+	if !epsilonEquals(result, expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}
+
+func TestMonthDifferenceT1AfterT2(t *testing.T) {
+	t1 := time.Date(2022, 6, 1, 0, 0, 0, 0, time.UTC)
+	t2 := time.Date(2022, 1, 1, 0, 0, 0, 0, time.UTC)
+	expected := -5.0
+	result := MonthDifference(t2, t1)
+	if !epsilonEquals(result, expected) {
+		t.Errorf("Expected %v, got %v", expected, result)
+	}
+}

timeext/time.go

@@ -184,3 +184,10 @@ func AddYears(t time.Time, yearCount float64, tz *time.Location) time.Time {
 
 	return t.Add(time.Duration(float64(t1.Sub(t0)) * floatCount))
 }
+
+func DaysInMonth(t time.Time) int {
+	// https://stackoverflow.com/a/73882035/1761622
+
+	y, m, _ := t.Date()
+	return time.Date(y, m+1, 0, 0, 0, 0, 0, time.UTC).Day()
+}

timeext/time_test.go

@@ -191,3 +191,39 @@ func TestCombineDateAndTime_CombineDifferentParts(t *testing.T) {
 		t.Errorf("Expected %v, got %v", expected, result)
 	}
 }
+
+func TestDaysInMonth_31Days(t *testing.T) {
+	date := time.Date(2022, 1, 1, 0, 0, 0, 0, time.UTC) // January
+	expected := 31
+	result := DaysInMonth(date)
+	if result != expected {
+		t.Errorf("Expected %d but got %d", expected, result)
+	}
+}
+
+func TestDaysInMonth_30Days(t *testing.T) {
+	date := time.Date(2022, 4, 1, 0, 0, 0, 0, time.UTC) // April
+	expected := 30
+	result := DaysInMonth(date)
+	if result != expected {
+		t.Errorf("Expected %d but got %d", expected, result)
+	}
+}
+
+func TestDaysInMonth_FebruaryLeapYear(t *testing.T) {
+	date := time.Date(2020, 2, 1, 0, 0, 0, 0, time.UTC) // February in a leap year
+	expected := 29
+	result := DaysInMonth(date)
+	if result != expected {
+		t.Errorf("Expected %d but got %d", expected, result)
+	}
+}
+
+func TestDaysInMonth_FebruaryNonLeapYear(t *testing.T) {
+	date := time.Date(2021, 2, 1, 0, 0, 0, 0, time.UTC) // February in a non-leap year
+	expected := 28
+	result := DaysInMonth(date)
+	if result != expected {
+		t.Errorf("Expected %d but got %d", expected, result)
+	}
+}