diff --git a/components/collections/actions/actions.ts b/components/collections/actions/actions.ts
index 588e8d8..af174cf 100644
--- a/components/collections/actions/actions.ts
+++ b/components/collections/actions/actions.ts
@@ -149,7 +149,7 @@ export type DispatchExecuteArgs = {
   | { type: Select<'batch_mint'>; recipient: string; batchNumber: number }
   | { type: Select<'set_whitelist'>; whitelist: string }
   | { type: Select<'update_start_time'>; startTime: string }
-  | { type: Select<'update_start_trading_time'>; startTime: string }
+  | { type: Select<'update_start_trading_time'>; startTime?: string }
   | { type: Select<'update_per_address_limit'>; limit: number }
   | { type: Select<'shuffle'> }
   | { type: Select<'withdraw'> }
@@ -259,7 +259,7 @@ export const previewExecutePayload = (args: DispatchExecuteArgs) => {
       return minterMessages(minterContract)?.updateStartTime(args.startTime)
     }
     case 'update_start_trading_time': {
-      return minterMessages(minterContract)?.updateStartTradingTime(args.startTime)
+      return minterMessages(minterContract)?.updateStartTradingTime(args.startTime as string)
     }
     case 'update_per_address_limit': {
       return minterMessages(minterContract)?.updatePerAddressLimit(args.limit)
diff --git a/contracts/minter/contract.ts b/contracts/minter/contract.ts
index eb77006..db89d9e 100644
--- a/contracts/minter/contract.ts
+++ b/contracts/minter/contract.ts
@@ -33,7 +33,7 @@ export interface MinterInstance {
   updateMintPrice: (senderAddress: string, price: string) => Promise<string>
   setWhitelist: (senderAddress: string, whitelist: string) => Promise<string>
   updateStartTime: (senderAddress: string, time: Timestamp) => Promise<string>
-  updateStartTradingTime: (senderAddress: string, time: Timestamp) => Promise<string>
+  updateStartTradingTime: (senderAddress: string, time?: Timestamp) => Promise<string>
   updatePerAddressLimit: (senderAddress: string, perAddressLimit: number) => Promise<string>
   mintTo: (senderAddress: string, recipient: string) => Promise<string>
   mintFor: (senderAddress: string, recipient: string, tokenId: number) => Promise<string>
@@ -325,7 +325,7 @@ export const minter = (client: SigningCosmWasmClient, txSigner: string): MinterC
         senderAddress,
         contractAddress,
         {
-          update_start_time: { time },
+          update_start_time: time,
         },
         'auto',
         '',
@@ -334,12 +334,12 @@ export const minter = (client: SigningCosmWasmClient, txSigner: string): MinterC
       return res.transactionHash
     }
 
-    const updateStartTradingTime = async (senderAddress: string, time: Timestamp): Promise<string> => {
+    const updateStartTradingTime = async (senderAddress: string, time?: Timestamp): Promise<string> => {
       const res = await client.execute(
         senderAddress,
         contractAddress,
         {
-          update_start_trading_time: { time },
+          update_start_trading_time: time || null,
         },
         'auto',
         '',
diff --git a/contracts/minter/messages/execute.ts b/contracts/minter/messages/execute.ts
index b57f45b..f2f072f 100644
--- a/contracts/minter/messages/execute.ts
+++ b/contracts/minter/messages/execute.ts
@@ -101,7 +101,7 @@ export type DispatchExecuteArgs = {
   | { type: Select<'update_mint_price'>; price: string }
   | { type: Select<'set_whitelist'>; whitelist: string }
   | { type: Select<'update_start_time'>; startTime: string }
-  | { type: Select<'update_start_trading_time'>; startTime: string }
+  | { type: Select<'update_start_trading_time'>; startTime?: string }
   | { type: Select<'update_per_address_limit'>; limit: number }
   | { type: Select<'mint_to'>; recipient: string }
   | { type: Select<'mint_for'>; recipient: string; tokenId: number }
@@ -179,7 +179,7 @@ export const previewExecutePayload = (args: DispatchExecuteArgs) => {
       return messages(contract)?.updateStartTime(args.startTime)
     }
     case 'update_start_trading_time': {
-      return messages(contract)?.updateStartTradingTime(args.startTime)
+      return messages(contract)?.updateStartTradingTime(args.startTime as string)
     }
     case 'update_per_address_limit': {
       return messages(contract)?.updatePerAddressLimit(args.limit)
diff --git a/pages/contracts/minter/execute.tsx b/pages/contracts/minter/execute.tsx
index 15747ec..302854f 100644
--- a/pages/contracts/minter/execute.tsx
+++ b/pages/contracts/minter/execute.tsx
@@ -80,7 +80,7 @@ const MinterExecutePage: NextPage = () => {
   })
 
   const showWhitelistField = type === 'set_whitelist'
-  const showDateField = type === 'update_start_time'
+  const showDateField = isEitherType(type, ['update_start_time', 'update_start_trading_time'])
   const showLimitField = type === 'update_per_address_limit'
   const showTokenIdField = type === 'mint_for'
   const showRecipientField = isEitherType(type, ['mint_to', 'mint_for'])