Fix case sensitivity with T, Z, and E.

src/datetime.rs

@@ -173,8 +173,9 @@ impl FromStr for Datetime {
         };
 
         // Next parse the "partial-time" if available
+        let next = chars.clone().next();
         let partial_time = if full_date.is_some()
-            && (chars.clone().next() == Some('T') || chars.clone().next() == Some(' '))
+            && (next == Some('T') || next == Some('t') || next == Some(' '))
         {
             chars.next();
             true
@@ -253,7 +254,7 @@ impl FromStr for Datetime {
         // And finally, parse the offset
         let offset = if offset_allowed {
             let next = chars.clone().next();
-            if next == Some('Z') {
+            if next == Some('Z') || next == Some('z') {
                 chars.next();
                 Some(Offset::Z)
             } else if next.is_none() {

src/de.rs

@@ -1169,7 +1169,10 @@ impl<'a> Deserializer<'a> {
     }
 
     fn number_or_date(&mut self, span: Span, s: &'a str) -> Result<Value<'a>, Error> {
-        if s.contains('T') || (s.len() > 1 && s[1..].contains('-')) && !s.contains("e-") {
+        if s.contains('T')
+            || s.contains('t')
+            || (s.len() > 1 && s[1..].contains('-') && !s.contains("e-") && !s.contains("E-"))
+        {
             self.datetime(span, s, false)
                 .map(|(Span { start, end }, d)| Value {
                     e: E::Datetime(d),

test-suite/tests/datetime.rs

@@ -14,6 +14,8 @@ fn times() {
     fn good(s: &str) {
         dogood(s, s);
         dogood(&s.replace("T", " "), s);
+        dogood(&s.replace("T", "t"), s);
+        dogood(&s.replace("Z", "z"), s);
     }
 
     good("1997-09-09T09:09:09Z");

test-suite/tests/parser.rs

@@ -227,6 +227,7 @@ fn floats() {
     t!("1.0e0", 1.0);
     t!("1.0e+0", 1.0);
     t!("1.0e-0", 1.0);
+    t!("1E-0", 1.0);
     t!("1.001e-0", 1.001);
     t!("2e10", 2e10);
     t!("2e+10", 2e10);