Add cron parser for start time of a reminder

src/commands/autocomplete.rs

@@ -3,6 +3,7 @@ use std::time::{SystemTime, UNIX_EPOCH};
 use chrono_tz::TZ_VARIANTS;
 use poise::serenity_prelude::AutocompleteChoice;
 
+use crate::time_parser::cron_next_timestamp;
 use crate::{models::CtxData, time_parser::natural_parser, Context};
 
 pub async fn timezone_autocomplete(ctx: Context<'_>, partial: &str) -> Vec<String> {
@@ -42,7 +43,13 @@ pub async fn time_hint_autocomplete(ctx: Context<'_>, partial: &str) -> Vec<Auto
     if partial.is_empty() {
         vec![AutocompleteChoice::new("Start typing a time...".to_string(), "now".to_string())]
     } else {
-        match natural_parser(partial, &ctx.timezone().await.to_string()).await {
+        let timezone = ctx.timezone().await;
+        let timestamp = match cron_next_timestamp(partial, timezone) {
+            Some(ts) => Some(ts),
+            None => natural_parser(partial, &timezone.to_string()).await,
+        };
+
+        match timestamp {
             Some(timestamp) => match SystemTime::now().duration_since(UNIX_EPOCH) {
                 Ok(now) => {
                     let diff = timestamp - now.as_secs() as i64;