use implementation from chrono#883 for begin-of-day

risuto-api/src/lib.rs

@@ -54,3 +54,30 @@ pub fn validate_time(s: &Time) -> Result<(), Error> {
         Ok(())
     }
 }
+
+// See https://github.com/chronotope/chrono/issues/948
+pub fn midnight_on<Tz>(date: chrono::NaiveDate, tz: &Tz) -> chrono::DateTime<Tz>
+where
+    Tz: Clone + std::fmt::Debug + chrono::TimeZone,
+{
+    let base = chrono::NaiveTime::MIN;
+    for multiple in 0..=24 {
+        let start_time = base + chrono::Duration::minutes(multiple * 15);
+        match date.and_time(start_time).and_local_timezone(tz.clone()) {
+            chrono::LocalResult::None => continue,
+            chrono::LocalResult::Single(dt) => return dt,
+            chrono::LocalResult::Ambiguous(dt1, dt2) => {
+                if dt1.naive_utc() < dt2.naive_utc() {
+                    return dt1;
+                } else {
+                    return dt2;
+                }
+            }
+        }
+    }
+
+    panic!(
+        "Unable to calculate start time for date {} and time zone {:?}",
+        date, tz
+    )
+}

risuto-api/src/query.rs

@@ -42,8 +42,7 @@ impl TimeQuery {
                         .map(|d| chrono::naive::Days::new(d as u64))
                         .and_then(|offset| date.checked_sub_days(offset)),
                 };
-                date.and_then(|d| d.and_hms_opt(0, 0, 0))
-                    .and_then(|d| d.and_local_timezone(*timezone).single())
+                date.map(|d| crate::midnight_on(d, timezone))
                     .map(|d| d.with_timezone(&chrono::Utc))
                     .ok_or(Error::IntegerOutOfRange(*day_offset))
             }

risuto-client/src/query.rs

@@ -6,7 +6,7 @@ use crate::{
 };
 
 use pest::{iterators::Pairs, pratt_parser::PrattParser, Parser as PestParser};
-use risuto_api::Error;
+use risuto_api::{midnight_on, Error};
 
 pub trait QueryExt {
     fn from_search(db: &DbDump, tz: &chrono_tz::Tz, search: &str) -> Query;
@@ -292,13 +292,12 @@ fn parse_date_cmp(
     let timequery = match timequery.as_rule() {
         Rule::abstimeq => TimeQuery::Absolute(
             // TODO: for safety, see (currently open) https://github.com/chronotope/chrono/pull/927
-            chrono::NaiveDate::parse_from_str(timequery.as_str(), "%Y-%m-%d")
-                .expect("parsing date cmp with ill-formed absolute date")
-                .and_hms_opt(0, 0, 0)
-                .expect("failed adding hms 000 to date")
-                .and_local_timezone(tz.clone())
-                .unwrap()
-                .with_timezone(&chrono::Utc),
+            midnight_on(
+                chrono::NaiveDate::parse_from_str(timequery.as_str(), "%Y-%m-%d")
+                    .expect("parsing date cmp with ill-formed absolute date"),
+                tz,
+            )
+            .with_timezone(&chrono::Utc),
         ),
         Rule::reltimeq => {
             let mut reader = timequery.into_inner();
@@ -341,7 +340,10 @@ fn parse_date_cmp(
     }
 }
 
-fn start_of_next_day(tz: &impl chrono::TimeZone, day: TimeQuery) -> TimeQuery {
+fn start_of_next_day<Tz>(tz: &Tz, day: TimeQuery) -> TimeQuery
+where
+    Tz: Clone + std::fmt::Debug + chrono::TimeZone,
+{
     match day {
         TimeQuery::DayRelative {
             timezone,
@@ -351,15 +353,13 @@ fn start_of_next_day(tz: &impl chrono::TimeZone, day: TimeQuery) -> TimeQuery {
             day_offset: day_offset + 1,
         },
         TimeQuery::Absolute(t) => TimeQuery::Absolute(
-            // TODO: for safety, see (currently open) https://github.com/chronotope/chrono/pull/927
-            t.date_naive()
-                .succ_opt()
-                .expect("failed figuring out a date for day+1")
-                .and_hms_opt(0, 0, 0)
-                .expect("failed setting hms to 000")
-                .and_local_timezone(tz.clone())
-                .unwrap()
-                .with_timezone(&chrono::Utc),
+            midnight_on(
+                t.date_naive()
+                    .succ_opt()
+                    .expect("failed figuring out a date for day+1"),
+                tz,
+            )
+            .with_timezone(&chrono::Utc),
         ),
     }
 }

risuto-server/src/query.rs

@@ -1,4 +1,4 @@
-use risuto_api::{Query, Time, TimeQuery, Uuid};
+use risuto_api::{midnight_on, Query, Time, TimeQuery, Uuid};
 
 use crate::error::Error;
 
@@ -129,11 +129,7 @@ fn timeq_to_bind(q: &TimeQuery) -> Result<Bind, Error> {
                     .checked_sub_days(chrono::naive::Days::new((-day_offset) as u64))
                     .ok_or_else(|| Error::integer_out_of_range(*day_offset))?,
             };
-            date.and_hms_opt(0, 0, 0)
-                .expect("naive_date and hms 000 failed")
-                .and_local_timezone(timezone.clone())
-                .unwrap()
-                .with_timezone(&chrono::Utc)
+            midnight_on(date, timezone).with_timezone(&chrono::Utc)
         }
     }))
 }

risuto-web/src/ui/task_list_item.rs

@@ -237,15 +237,10 @@ fn timeset_button(p: &TimesetButtonProps) -> Html {
     let timeset_label = current_date
         .and_then(|d| {
             let remaining = d.signed_duration_since(chrono::Utc::now());
-            // TODO: for safety, see (currently open) https://github.com/chronotope/chrono/pull/927
-            let since_beginning_of_day = d.signed_duration_since(
-                chrono::Utc::now()
-                    .date_naive()
-                    .and_hms_opt(0, 0, 0)
-                    .expect("failed figuring out the start of day")
-                    .and_local_timezone(util::local_tz())
-                    .unwrap(),
-            );
+            let since_beginning_of_day = d.signed_duration_since(midnight_on(
+                chrono::Utc::now().date_naive(),
+                util::local_tz(),
+            ));
             match remaining {
                 r if r > chrono::Duration::days(365) => Some(format!("{}", d.year())),
                 r if r > chrono::Duration::days(1) => Some(format!("{}/{}", d.month(), d.day())),