From 2b4253caf9e6846b88310575768449191d8a9ba9 Mon Sep 17 00:00:00 2001
From: Leo Developer <leo@git.leodev.win>
Date: Thu, 4 Sep 2025 23:22:52 +0200
Subject: [PATCH] time: always return utc() timezone for Time.unix/0 (fix
 #17784) (#25233)

---
 vlib/orm/orm_test.v          |  4 +++-
 vlib/time/operator.v         |  7 +++++--
 vlib/time/private_test.c.v   | 14 --------------
 vlib/time/time.v             | 30 ++++++++++++++++++++++++------
 vlib/time/time_format_test.v |  2 +-
 vlib/time/time_test.c.v      |  2 +-
 vlib/time/time_test.v        | 17 -----------------
 vlib/v/gen/c/json.v          |  8 ++++----
 8 files changed, 38 insertions(+), 46 deletions(-)
 delete mode 100644 vlib/time/private_test.c.v

diff --git a/vlib/orm/orm_test.v b/vlib/orm/orm_test.v
index c6eebc747a..5b5be2180f 100644
--- a/vlib/orm/orm_test.v
+++ b/vlib/orm/orm_test.v
@@ -393,7 +393,9 @@ fn test_orm() {
 	// Note: usually updated_time_mod.created != t, because t has
 	// its microseconds set, while the value retrieved from the DB
 	// has them zeroed, because the db field resolution is seconds.
-	assert modules.first().created.format_ss() == t.format_ss()
+	// Note: the database also stores the time in UTC, so the
+	// comparison must be done on the unix timestamp.
+	assert modules.first().created.unix() == t.unix()
 
 	users = sql db {
 		select from User where (name == 'Sam' && is_customer == true) || id == 1
diff --git a/vlib/time/operator.v b/vlib/time/operator.v
index 8c5fab8e89..8242e3444e 100644
--- a/vlib/time/operator.v
+++ b/vlib/time/operator.v
@@ -3,13 +3,16 @@ module time
 // operator `==` returns true if provided time is equal to time
 @[inline]
 pub fn (t1 Time) == (t2 Time) bool {
-	return t1.unix() == t2.unix() && t1.nanosecond == t2.nanosecond
+	return t1.is_local == t2.is_local && t1.local_unix() == t2.local_unix()
+		&& t1.nanosecond == t2.nanosecond
 }
 
 // operator `<` returns true if provided time is less than time
 @[inline]
 pub fn (t1 Time) < (t2 Time) bool {
-	return t1.unix() < t2.unix() || (t1.unix() == t2.unix() && t1.nanosecond < t2.nanosecond)
+	t1u := t1.unix()
+	t2u := t2.unix()
+	return t1u < t2u || (t1u == t2u && t1.nanosecond < t2.nanosecond)
 }
 
 // Time subtract using operator overloading.
diff --git a/vlib/time/private_test.c.v b/vlib/time/private_test.c.v
deleted file mode 100644
index 7e69c40374..0000000000
--- a/vlib/time/private_test.c.v
+++ /dev/null
@@ -1,14 +0,0 @@
-// tests that use and test private functions
-module time
-
-// test the old behavior is same as new, the unix time should always be local time
-fn test_new_is_same_as_old_for_all_platforms() {
-	t := C.time(0)
-	tm := C.localtime(&t)
-	old_time := convert_ctime(tm, 0)
-	new_time := now()
-	diff := new_time.unix - old_time.unix
-	// could in very rare cases be that the second changed between calls
-	dump(diff)
-	assert (diff >= -2 && diff <= 2) == true
-}
diff --git a/vlib/time/time.v b/vlib/time/time.v
index 9e18c8ef52..c9b1059a4d 100644
--- a/vlib/time/time.v
+++ b/vlib/time/time.v
@@ -106,6 +106,12 @@ pub fn (t Time) smonth() string {
 // unix returns the UNIX time with second resolution.
 @[inline]
 pub fn (t Time) unix() i64 {
+	return time_with_unix(t.local_to_utc()).unix
+}
+
+// local_unix returns the UNIX local time with second resolution.
+@[inline]
+pub fn (t Time) local_unix() i64 {
 	return time_with_unix(t).unix
 }
 
@@ -135,14 +141,26 @@ pub fn (t Time) add(duration_in_nanosecond Duration) Time {
 	// ... so instead, handle the addition manually in parts ¯\_(ツ)_/¯
 	mut increased_time_nanosecond := i64(t.nanosecond) + duration_in_nanosecond.nanoseconds()
 	// increased_time_second
-	mut increased_time_second := t.unix() + (increased_time_nanosecond / second)
+	mut increased_time_second := t.local_unix() + (increased_time_nanosecond / second)
 	increased_time_nanosecond = increased_time_nanosecond % second
 	if increased_time_nanosecond < 0 {
 		increased_time_second--
 		increased_time_nanosecond += second
 	}
 	res := unix_nanosecond(increased_time_second, int(increased_time_nanosecond))
-	return if t.is_local { res.as_local() } else { res }
+
+	if t.is_local {
+		// we need to reset unix to 0, because we don't know the offset
+		// and we can't calculate it without it without causing infinite recursion
+		// so unfortunately we need to recalculate unix next time it is needed
+		return Time{
+			...res
+			is_local: true
+			unix:     0
+		}
+	}
+
+	return res
 }
 
 // add_seconds returns a new time struct with an added number of seconds.
@@ -177,7 +195,7 @@ pub fn since(t Time) Duration {
 // ```
 pub fn (t Time) relative() string {
 	znow := now()
-	mut secs := znow.unix - t.unix()
+	mut secs := znow.unix() - t.unix()
 	mut prefix := ''
 	mut suffix := ''
 	if secs < 0 {
@@ -239,7 +257,7 @@ pub fn (t Time) relative() string {
 // ```
 pub fn (t Time) relative_short() string {
 	znow := now()
-	mut secs := znow.unix - t.unix()
+	mut secs := znow.unix() - t.unix()
 	mut prefix := ''
 	mut suffix := ''
 	if secs < 0 {
@@ -364,9 +382,9 @@ pub fn days_in_month(month int, year int) !int {
 	return res
 }
 
-// debug returns detailed breakdown of time (`Time{ year: YYYY month: MM day: dd hour: HH: minute: mm second: ss nanosecond: nanos unix: unix }`).
+// debug returns detailed breakdown of time (`Time{ year: YYYY month: MM day: dd hour: HH: minute: mm second: ss nanosecond: nanos unix: unix is_local: false }`).
 pub fn (t Time) debug() string {
-	return 'Time{ year: ${t.year:04} month: ${t.month:02} day: ${t.day:02} hour: ${t.hour:02} minute: ${t.minute:02} second: ${t.second:02} nanosecond: ${t.nanosecond:09} unix: ${t.unix:07} }'
+	return 'Time{ year: ${t.year:04} month: ${t.month:02} day: ${t.day:02} hour: ${t.hour:02} minute: ${t.minute:02} second: ${t.second:02} nanosecond: ${t.nanosecond:09} unix: ${t.unix:07} is_local: ${t.is_local} }'
 }
 
 // offset returns time zone UTC offset in seconds.
diff --git a/vlib/time/time_format_test.v b/vlib/time/time_format_test.v
index 8ca07ac5d4..f21be4061a 100644
--- a/vlib/time/time_format_test.v
+++ b/vlib/time/time_format_test.v
@@ -12,7 +12,7 @@ const time_to_test = time.Time{
 fn test_now_format() {
 	t := time.now()
 	u := t.unix()
-	assert t.format() == time.unix(int(u)).format()
+	assert t.format() == time.unix(int(u)).utc_to_local().format()
 }
 
 fn test_format() {
diff --git a/vlib/time/time_test.c.v b/vlib/time/time_test.c.v
index 2222e1e2d6..7bf896608d 100644
--- a/vlib/time/time_test.c.v
+++ b/vlib/time/time_test.c.v
@@ -15,7 +15,7 @@ fn test_tm_gmtoff() {
 		dump(t2)
 		dump(t1.nanosecond)
 		dump(t2.nanosecond)
-		diff := int(t1.unix() - t2.unix())
+		diff := int(t1.local_unix() - t2.unix())
 		dump(diff)
 		dump(info.tm_gmtoff)
 		assert diff in [info.tm_gmtoff - 1, info.tm_gmtoff, info.tm_gmtoff + 1]
diff --git a/vlib/time/time_test.v b/vlib/time/time_test.v
index 34554cab82..e33b0e5c2e 100644
--- a/vlib/time/time_test.v
+++ b/vlib/time/time_test.v
@@ -90,17 +90,10 @@ fn test_unix() {
 	assert t6.hour == 6
 	assert t6.minute == 9
 	assert t6.second == 29
-	assert local_time_to_test.unix() == 332198622
 	assert utc_time_to_test.unix() == 332198622
 }
 
 fn test_format_rfc3339() {
-	// assert '1980-07-11T19:23:42.123Z'
-	res := local_time_to_test.format_rfc3339()
-	assert res.ends_with('23:42.123Z')
-	assert res.starts_with('1980-07-1')
-	assert res.contains('T')
-
 	// assert '1980-07-11T19:23:42.123Z'
 	utc_res := utc_time_to_test.format_rfc3339()
 	assert utc_res.ends_with('23:42.123Z')
@@ -109,11 +102,6 @@ fn test_format_rfc3339() {
 }
 
 fn test_format_rfc3339_micro() {
-	res := local_time_to_test.format_rfc3339_micro()
-	assert res.ends_with('23:42.123456Z')
-	assert res.starts_with('1980-07-1')
-	assert res.contains('T')
-
 	utc_res := utc_time_to_test.format_rfc3339_micro()
 	assert utc_res.ends_with('23:42.123456Z')
 	assert utc_res.starts_with('1980-07-1')
@@ -121,11 +109,6 @@ fn test_format_rfc3339_micro() {
 }
 
 fn test_format_rfc3339_nano() {
-	res := local_time_to_test.format_rfc3339_nano()
-	assert res.ends_with('23:42.123456789Z')
-	assert res.starts_with('1980-07-1')
-	assert res.contains('T')
-
 	utc_res := utc_time_to_test.format_rfc3339_nano()
 	assert utc_res.ends_with('23:42.123456789Z')
 	assert utc_res.starts_with('1980-07-1')
diff --git a/vlib/v/gen/c/json.v b/vlib/v/gen/c/json.v
index db30ad49bd..7b102074aa 100644
--- a/vlib/v/gen/c/json.v
+++ b/vlib/v/gen/c/json.v
@@ -417,7 +417,7 @@ fn (mut g Gen) gen_sumtype_enc_dec(utyp ast.Type, sym ast.TypeSymbol, mut enc st
 			if variant_sym.kind == .enum {
 				enc.writeln('\t\tcJSON_AddItemToObject(o, "${unmangled_variant_name}", ${js_enc_name('u64')}(*${var_data}${field_op}_${variant_typ}));')
 			} else if variant_sym.name == 'time.Time' {
-				enc.writeln('\t\tcJSON_AddItemToObject(o, "${unmangled_variant_name}", ${js_enc_name('i64')}(${var_data}${field_op}_${variant_typ}->__v_unix));')
+				enc.writeln('\t\tcJSON_AddItemToObject(o, "${unmangled_variant_name}", ${js_enc_name('i64')}(time__Time_unix(*${var_data}${field_op}_${variant_typ})));')
 			} else {
 				enc.writeln('\t\tcJSON_AddItemToObject(o, "${unmangled_variant_name}", ${js_enc_name(variant_typ)}(*${var_data}${field_op}_${variant_typ}));')
 			}
@@ -442,7 +442,7 @@ fn (mut g Gen) gen_sumtype_enc_dec(utyp ast.Type, sym ast.TypeSymbol, mut enc st
 				}
 			} else if variant_sym.name == 'time.Time' {
 				enc.writeln('\t\tcJSON_AddItemToObject(o, "_type", cJSON_CreateString("${unmangled_variant_name}"));')
-				enc.writeln('\t\tcJSON_AddItemToObject(o, "value", ${js_enc_name('i64')}(${var_data}${field_op}_${variant_typ}->__v_unix));')
+				enc.writeln('\t\tcJSON_AddItemToObject(o, "value", ${js_enc_name('i64')}(time__Time_unix(*${var_data}${field_op}_${variant_typ})));')
 			} else {
 				enc.writeln('\t\tcJSON_free(o);')
 				enc.writeln('\t\to = ${js_enc_name(variant_typ)}(*${var_data}${field_op}_${variant_typ});')
@@ -954,9 +954,9 @@ fn (mut g Gen) gen_struct_enc_dec(utyp ast.Type, type_info ast.TypeInfo, styp st
 				// time struct requires special treatment
 				// it has to be encoded as a unix timestamp number
 				if is_option {
-					enc.writeln('${indent}cJSON_AddItemToObject(o, "${name}", json__encode_u64((*(${g.base_type(field.typ)}*)(${prefix_enc}${op}${c_name(field.name)}.data)).__v_unix));')
+					enc.writeln('${indent}cJSON_AddItemToObject(o, "${name}", json__encode_u64(time__Time_unix(*(${g.base_type(field.typ)}*)(${prefix_enc}${op}${c_name(field.name)}.data))));')
 				} else {
-					enc.writeln('${indent}cJSON_AddItemToObject(o, "${name}", json__encode_u64(${prefix_enc}${op}${c_name(field.name)}.__v_unix));')
+					enc.writeln('${indent}cJSON_AddItemToObject(o, "${name}", json__encode_u64(time__Time_unix(${prefix_enc}${op}${c_name(field.name)})));')
 				}
 			} else {
 				if !field.typ.is_any_kind_of_pointer() {