Clarifies that strings are still allowed as arguments, but not when a date is expected.

Author: bradevans

docs/upgradeGuide.md

@@ -24,7 +24,7 @@ See [Unicode Tokens doc](https://date-fns.org/docs/Unicode-Tokens) for more deta
 
 ### String arguments
 
-Functions now don't accept strings as arguments. Strings should
+Functions now don't accept strings as date arguments. Strings should
 be parsed using `parseISO` (ISO 8601) or `parse`.
 
 See [this post](https://blog.date-fns.org/post/we-cut-date-fns-v2-minimal-build-size-down-to-300-bytes-and-now-its-the-smallest-date-library-18f2nvh2z0yal) for more details.

src/toDate/index.js

@@ -51,7 +51,7 @@ export default function toDate(argument) {
     ) {
       // eslint-disable-next-line no-console
       console.warn(
-        "Starting with v2.0.0-beta.1 date-fns doesn't accept strings as arguments. Please use `parseISO` to parse strings. See: https://git.io/fjule"
+        "Starting with v2.0.0-beta.1 date-fns doesn't accept strings as date arguments. Please use `parseISO` to parse strings. See: https://git.io/fjule"
       )
       // eslint-disable-next-line no-console
       console.warn(new Error().stack)

src/toDate/test.js

@@ -41,7 +41,7 @@ describe('toDate', () => {
       assert(
         // eslint-disable-next-line no-console
         console.warn.calledWith(
-          "Starting with v2.0.0-beta.1 date-fns doesn't accept strings as arguments. Please use `parseISO` to parse strings. See: https://git.io/fjule"
+          "Starting with v2.0.0-beta.1 date-fns doesn't accept strings as date arguments. Please use `parseISO` to parse strings. See: https://git.io/fjule"
         )
       )
     })