separaded endpoints + cleaned page templates + added constants to time formatting

Backend/helper/paramParser/main.go

@@ -0,0 +1,31 @@
+package paramParser
+
+import (
+	"log/slog"
+	"net/url"
+	"time"
+)
+
+type ParamsParser struct {
+	urlParams url.Values
+}
+
+func New(_urlParams url.Values) ParamsParser {
+	return ParamsParser{
+		urlParams: _urlParams,
+	}
+}
+
+func (p *ParamsParser) ParseTimestamp(key string, format string, fallback time.Time) time.Time {
+	paramTimestamp := p.urlParams.Get(key)
+	if paramTimestamp == "" {
+		return fallback
+	}
+	if timestamp, err := time.Parse(format, paramTimestamp); err == nil {
+		return timestamp
+	} else {
+		slog.Warn("Error parsing HTTP Params to timestamp", slog.Any("key", key), slog.Any("error", err))
+		return fallback
+	}
+
+}