Start to build a test query for caching layer

err/Cargo.toml

@@ -9,3 +9,4 @@ hyper = { version = "0.14", features = ["http1", "http2", "client", "server", "t
 http = "0.2"
 serde_json = "1.0"
 async-channel = "1.6"
+chrono = { version = "0.4.19", features = ["serde"] }

err/src/lib.rs

@@ -67,3 +67,11 @@ impl From<async_channel::RecvError> for Error {
         }
     }
 }
+
+impl From<chrono::format::ParseError> for Error {
+    fn from (k: chrono::format::ParseError) -> Self {
+        Self {
+            msg: k.to_string(),
+        }
+    }
+}