Replaced use of String.starts_with in timedesc-tzlocal

Author: darrenldl

CHANGELOG.md

@@ -18,6 +18,10 @@
 
     - See [issue #78](https://github.com/daypack-dev/timere/issues/78)
 
+## Timedesc 3.1.2
+
+- Removed use of `String.starts_with` in `timedesc-tzlocal` so it builds on OCaml 4.11
+
 ## Timedesc 3.1.1
 
 - Refreshed tzdb

timedesc-tzlocal/unix/timedesc_tzlocal.ml

@@ -36,7 +36,7 @@ let local () : string list =
   match Sys.getenv_opt "TZ" with
   | Some name -> (
       let name =
-        if String.starts_with ~prefix:":" name then (
+        if name.[0] = ':' then (
           String.sub name 1 (String.length name - 1)
         ) else (
           name