Stone Calendar 
Artifact
$14.91 #20542 0.37 32.2 years
Spells you cast cost 
less to cast.
less to cast.Click a line or tag to filter
Cards similar to Stone Calendar expected a card that isn't here?
Reports become test cases the matcher is graded against before an update ships. Delvefall isn't a chatbot guessing, it compares the printed rules text of every card with plain math, and examples like yours decide which differences should count.
Helm of Awakening94%
$1.61↓#1927↑0.3229.7 years↓
"Spells cost less to cast."
less to cast."
Spellwild Ouphe90%
$0.29↓#166900.09↓19.5 years↓
"Spells that target this creature cost 
less to cast."
less to cast."
Memory Crystal89%
$2.23↓#240890.19↓28.3 years↓
"Buyback costs cost less."
less."
Pearl Medallion86%
$7.43↓#429↑0.19↓29.0 years↓
"White spells you cast cost less to cast."
less to cast."
Killian, Ink Duelist85%
$0.31↓#3410↑0.285.5 years↓
"Spells you cast that target a creature cost less to cast."
less to cast."
Sapphire Medallion85%
$7.87↓#354↑0.3429.0 years↓
"Blue spells you cast cost less to cast."
less to cast."
Uthros Psionicist84%
$0.22↓#9584↑0.22↓1.2 years↓
"The second spell you cast each turn costs less to cast."
less to cast."
Umori, the Collector84%
$0.31↓#10770↑0.00↓6.5 years↓
"Spells you cast of the chosen type cost less to cast."
less to cast."
Raging Battle Mouse84%
$0.22↓#12427↑0.00↓3.1 years↓
"The second spell you cast each turn costs less to cast."
less to cast."
The Immortal Sun84%
$11.99↓#2652↑0.89↑8.8 years↓
"Spells you cast cost less to cast."
less to cast."
Naiad of Hidden Coves84%
$0.22↓#10618↑0.06↓6.7 years↓
"During turns other than yours, spells you cast cost less to cast."
less to cast."
Highspire Bell-Ringer84%
$0.16↓#10943↑0.00↓1.5 years↓
"The second spell you cast each turn costs less to cast."
less to cast."
Emerald Medallion84%
$5.16↓#582↑0.3029.0 years↓
"Green spells you cast cost less to cast."
less to cast."
Geyser Drake83%
$0.13↓#8697↑0.19↓2.5 years↓
"During turns other than yours, spells you cast cost less to cast."
less to cast."
Hardened Berserker83%
$0.04↓#243520.00↓11.6 years↓
"Whenever this creature attacks, the next spell you cast this turn costs less to cast."
less to cast."
Ruby Medallion82%
$14.07↓#293↑0.2829.0 years↓
"Red spells you cast cost less to cast."
less to cast."
Racers' Scoreboard80%
$0.26↓#6383↑0.00↓1.7 years↓
"Max speed — Spells you cast cost less to cast."
less to cast."
Urza's Filter80%
$4.88↓#14664↑0.3026.0 years↓
"Multicolored spells cost less to cast."
less to cast."
Jet Medallion80%
$13.42↓#274↑0.2729.0 years↓
"Black spells you cast cost less to cast."
less to cast."
Council of the Absolute79%
$0.31↓#244660.53↑13.5 years↓
"Spells with the chosen name you cast cost less to cast."
less to cast."