️ Can use date with a + symbol for positiv year

src/Day.ts

@@ -40,7 +40,7 @@ export class Day implements DayInterface {
     }
 
     if (typeof data === 'string') {
-      if (/^-?\d+-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}/.test(data)) {
+      if (/^[-+]?\d+-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}/.test(data)) {
         const {
           year,
           month,
@@ -49,7 +49,7 @@ export class Day implements DayInterface {
           minute,
           second,
           millisecond,
-        } = /^(?<year>-?\d+)-(?<month>\d{2})-(?<day>\d{2})T(?<hour>\d{2}):(?<minute>\d{2}):(?<second>\d{2}).(?<millisecond>\d{3})/.exec(data)!.groups!
+        } = /^(?<year>[-+]?\d+)-(?<month>\d{2})-(?<day>\d{2})T(?<hour>\d{2}):(?<minute>\d{2}):(?<second>\d{2}).(?<millisecond>\d{3})/.exec(data)!.groups!
         this.#Y = parseInt(year)
         this.#M = parseInt(month)
         this.#D = parseInt(day)
@@ -60,7 +60,7 @@ export class Day implements DayInterface {
         return
       }
 
-      if (/^-?\d+-\d{2}-\d{2}$/.test(data)) {
+      if (/^[-+]?\d+-\d{2}-\d{2}$/.test(data)) {
         const [year, month, day] = /^(-?\d{4})-(\d{2})-(\d{2})/.exec(data)!.slice(1)
         this.#Y = parseInt(year)
         this.#M = parseInt(month)
@@ -68,7 +68,7 @@ export class Day implements DayInterface {
         return
       }
 
-      if (/^-?\d+\/\d{2}\/-?\d{2}$/.test(data)) {
+      if (/^[-+]?\d+\/\d{2}\/-?\d{2}$/.test(data)) {
         const [year, month, day] = data.split('/')
         this.#Y = parseInt(year)
         this.#M = parseInt(month)
@@ -125,7 +125,7 @@ export class Day implements DayInterface {
 
   static utc(data: string): Day {
     if (!data) throw new Error('Date is required')
-    if (!/^(-?\d+)-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})\.(\d{3})/.test(data)) {
+    if (!/^([-+]?\d+)-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})\.(\d{3})/.test(data)) {
       throw new Error(`Invalid date format. Use "YYYY-MM-DDTHH:MM:SS.SSSZ", data received: ${data}`)
     }
 
@@ -138,7 +138,7 @@ export class Day implements DayInterface {
       minute,
       second,
       millisecond,
-    ] = /^(-?\d+)-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})\.(\d{3})/.exec(data)!
+    ] = /^([-+]?\d+)-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})\.(\d{3})/.exec(data)!
     return new Day({
       year: parseInt(year),
       month: parseInt(month),