diff --git a/src/main.rs b/src/main.rs
index 308f2ce..9ae6518 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -106,9 +106,15 @@ fn log(f: &String, since: &Option<String>) -> Result<(), String> {
 fn parse_time(since: &Option<String>) -> Result<SystemTime, String> {
    match since {
       Some(since) => {
-         match DateTime::parse_from_str(since, "%Y-%m-%d") {
+         match chrono::NaiveDate::parse_from_str(since, "%Y-%m-%d") {
             Ok(dt) => {
-               Err("not impl".to_string())
+               Ok(UNIX_EPOCH.add(
+                  Duration::from_secs(
+                     dt.and_hms_opt(1, 1, 1)
+                        .unwrap()
+                        .timestamp() as u64
+                  )
+               ))
             },
             Err(msg) => Err(format!("failed to parse {}: {}", since, msg)),
          }