Handle DateTimes directly in the encoder

src/Stripe.net/Infrastructure/Middleware/RequestStringBuilder.cs

@@ -98,6 +98,15 @@ private static List<Parameter> FlattenParamsValue(object value, string keyPrefix
 
                 flatParams.Add(new Parameter(keyPrefix, paramValue));
             }
+            else if (value is DateTime)
+            {
+                flatParams = new List<Parameter>();
+                DateTime? dateTime = (DateTime)value;
+                if (dateTime.HasValue)
+                {
+                    flatParams.Add(new Parameter(keyPrefix, dateTime?.ConvertDateTimeToEpoch().ToString()));
+                }
+            }
             else if (value == null)
             {
                 flatParams = new List<Parameter>();

src/Stripe.net/Services/Account/StripeAccountSharedOptions.cs

@@ -69,21 +69,8 @@ public abstract class StripeAccountSharedOptions : StripeBaseOptions, ISupportMe
 
         #region Tos Acceptance
 
-        public DateTime? TosAcceptanceDate { get; set; }
-
         [JsonProperty("tos_acceptance[date]")]
-        internal long? TosAcceptanceDateInternal
-        {
-            get
-            {
-                if (!this.TosAcceptanceDate.HasValue)
-                {
-                    return null;
-                }
-
-                return EpochTime.ConvertDateTimeToEpoch(this.TosAcceptanceDate.Value);
-            }
-        }
+        public DateTime? TosAcceptanceDate { get; set; }
 
         [JsonProperty("tos_acceptance[ip]")]
         public string TosAcceptanceIp { get; set; }

src/Stripe.net/Services/Coupons/StripeCouponCreateOptions.cs

@@ -34,20 +34,7 @@ public class StripeCouponCreateOptions : StripeBaseOptions, ISupportMetadata
         [JsonProperty("name")]
         public string Name { get; set; }
 
-        public DateTime? RedeemBy { get; set; }
-
         [JsonProperty("redeem_by")]
-        internal long? RedeemByInternal
-        {
-            get
-            {
-                if (!this.RedeemBy.HasValue)
-                {
-                    return null;
-                }
-
-                return EpochTime.ConvertDateTimeToEpoch(this.RedeemBy.Value);
-            }
-        }
+        public DateTime? RedeemBy { get; set; }
     }
 }

src/Stripe.net/Services/FileLinks/StripeFileLinkSharedOptions.cs

@@ -10,21 +10,8 @@ public class StripeFileLinkSharedOptions : StripeBaseOptions, ISupportMetadata
         /// <summary>
         /// A future timestamp after which the link will no longer be usable.
         /// </summary>
-        public DateTime? ExpiresAt { get; set; }
-
         [JsonProperty("expires_at")]
-        internal long? ExpiresAtInternal
-        {
-            get
-            {
-                if (!this.ExpiresAt.HasValue)
-                {
-                    return null;
-                }
-
-                return EpochTime.ConvertDateTimeToEpoch(this.ExpiresAt.Value);
-            }
-        }
+        public DateTime? ExpiresAt { get; set; }
 
         /// <summary>
         /// Set of key-value pairs that you can attach to an object. This can be useful for storing

src/Stripe.net/Services/Invoices/StripeInvoiceCreateOptions.cs

@@ -28,10 +28,8 @@ public class StripeInvoiceCreateOptions : StripeBaseOptions, ISupportMetadata
         /// <summary>
         /// The date on which payment for this invoice is due. Only valid for invoices where billing=send_invoice.
         /// </summary>
-        public DateTime? DueDate { get; set; }
-
         [JsonProperty("due_date")]
-        internal long? DueDateInternal => this.DueDate?.ConvertDateTimeToEpoch();
+        public DateTime? DueDate { get; set; }
 
         [JsonProperty("metadata")]
         public Dictionary<string, string> Metadata { get; set; }
@@ -45,4 +43,4 @@ public class StripeInvoiceCreateOptions : StripeBaseOptions, ISupportMetadata
         [JsonProperty("tax_percent")]
         public decimal? TaxPercent { get; set; }
     }
-}
+}

src/Stripe.net/Services/Invoices/StripeUpcomingInvoiceOptions.cs

@@ -16,21 +16,8 @@ public class StripeUpcomingInvoiceOptions : StripeBaseOptions
         /// <summary>
         /// A future date to anchor the subscription’s <see href="https://stripe.com/docs/subscriptions/billing-cycle">billing cycle</see>. This is used to determine the date of the first full invoice, and, for plans with <c>month</c> or <c>year</c> intervals, the day of the month for subsequent invoices.
         /// </summary>
-        public DateTime? SubscriptionBillingCycleAnchor { get; set; }
-
         [JsonProperty("subscription_billing_cycle_anchor")]
-        internal long? SubscriptionBillingCycleAnchorInternal
-        {
-            get
-            {
-                if (!this.SubscriptionBillingCycleAnchor.HasValue)
-                {
-                    return null;
-                }
-
-                return EpochTime.ConvertDateTimeToEpoch(this.SubscriptionBillingCycleAnchor.Value);
-            }
-        }
+        public DateTime? SubscriptionBillingCycleAnchor { get; set; }
 
         [JsonProperty("subscription")]
         public string SubscriptionId { get; set; }
@@ -44,43 +31,17 @@ internal long? SubscriptionBillingCycleAnchorInternal
         [JsonProperty("subscription_prorate")]
         public bool? SubscriptionProrate { get; set; }
 
-        public DateTime? SubscriptionProrationDate { get; set; }
-
         [JsonProperty("subscription_proration_date")]
-        internal long? SubscriptionProrationDateInternal
-        {
-            get
-            {
-                if (!this.SubscriptionProrationDate.HasValue)
-                {
-                    return null;
-                }
-
-                return EpochTime.ConvertDateTimeToEpoch(this.SubscriptionProrationDate.Value);
-            }
-        }
+        public DateTime? SubscriptionProrationDate { get; set; }
 
         [JsonProperty("subscription_quantity")]
         public int? SubscriptionQuantity { get; set; }
 
         [JsonProperty("subscription_tax_percent")]
         public decimal? SubscriptionTaxPercent { get; set; }
 
-        public DateTime? SubscriptionTrialEnd { get; set; }
-
         [JsonProperty("subscription_trial_end")]
-        internal long? SubscriptionTrialEndInternal
-        {
-            get
-            {
-                if (!this.SubscriptionTrialEnd.HasValue)
-                {
-                    return null;
-                }
-
-                return EpochTime.ConvertDateTimeToEpoch(this.SubscriptionTrialEnd.Value);
-            }
-        }
+        public DateTime? SubscriptionTrialEnd { get; set; }
 
         [JsonProperty("subscription_trial_from_plan")]
         public bool? SubscriptionTrialFromPlan { get; set; }

src/Stripe.net/Services/Reporting/ReportRuns/ParametersOptions.cs

@@ -13,37 +13,11 @@ public class ParametersOptions : INestedOptions
         [JsonProperty("currency")]
         public string Currency { get; set; }
 
-        public DateTime? IntervalEnd { get; set; }
-
         [JsonProperty("interval_end")]
-        internal long? IntervalEndInternal
-        {
-            get
-            {
-                if (!this.IntervalEnd.HasValue)
-                {
-                    return null;
-                }
-
-                return EpochTime.ConvertDateTimeToEpoch(this.IntervalEnd.Value);
-            }
-        }
-
-        public DateTime? IntervalStart { get; set; }
+        public DateTime? IntervalEnd { get; set; }
 
         [JsonProperty("interval_start")]
-        internal long? IntervalStartInternal
-        {
-            get
-            {
-                if (!this.IntervalStart.HasValue)
-                {
-                    return null;
-                }
-
-                return EpochTime.ConvertDateTimeToEpoch(this.IntervalStart.Value);
-            }
-        }
+        public DateTime? IntervalStart { get; set; }
 
         [JsonProperty("payout")]
         public string Payout { get; set; }

src/Stripe.net/Services/Sources/StripeSourceMandateOptions.cs

@@ -6,21 +6,8 @@ namespace Stripe
 
     public class StripeSourceMandateOptions : INestedOptions
     {
-        public DateTime? MandateAcceptanceDate { get; set; }
-
         [JsonProperty("acceptance[date]")]
-        internal long? MandateAcceptanceDateInternal
-        {
-            get
-            {
-                if (!this.MandateAcceptanceDate.HasValue)
-                {
-                    return null;
-                }
-
-                return EpochTime.ConvertDateTimeToEpoch(this.MandateAcceptanceDate.Value);
-            }
-        }
+        public DateTime? MandateAcceptanceDate { get; set; }
 
         [JsonProperty("acceptance[ip]")]
         public string MandateAcceptanceIp { get; set; }

src/Stripe.net/Services/SubscriptionItems/SubscriptionItemSharedOptions.cs

@@ -21,21 +21,8 @@ public abstract class SubscriptionItemSharedOptions : StripeBaseOptions
         /// <summary>
         /// If set, the proration will be calculated as though the subscription was updated at the given time. This can be used to apply the same proration that was previewed with the upcoming invoice endpoint.
         /// </summary>
-        public DateTime? ProrationDate { get; set; }
-
         [JsonProperty("proration_date")]
-        internal long? ProrationDateInternal
-        {
-            get
-            {
-                if (!this.ProrationDate.HasValue)
-                {
-                    return null;
-                }
-
-                return this.ProrationDate.Value.ConvertDateTimeToEpoch();
-            }
-        }
+        public DateTime? ProrationDate { get; set; }
 
         /// <summary>
         /// The quantity you’d like to apply to the subscription item you’re creating.

src/Stripe.net/Services/Subscriptions/StripeSubscriptionCreateOptions.cs

@@ -10,21 +10,8 @@ public class StripeSubscriptionCreateOptions : SubscriptionSharedOptions
         /// <summary>
         /// A future date to anchor the subscription’s <see href="https://stripe.com/docs/subscriptions/billing-cycle">billing cycle</see>. This is used to determine the date of the first full invoice, and, for plans with <c>month</c> or <c>year</c> intervals, the day of the month for subsequent invoices.
         /// </summary>
-        public DateTime? BillingCycleAnchor { get; set; }
-
         [JsonProperty("billing_cycle_anchor")]
-        internal long? BillingCycleAnchorInternal
-        {
-            get
-            {
-                if (!this.BillingCycleAnchor.HasValue)
-                {
-                    return null;
-                }
-
-                return EpochTime.ConvertDateTimeToEpoch(this.BillingCycleAnchor.Value);
-            }
-        }
+        public DateTime? BillingCycleAnchor { get; set; }
 
         /// <summary>
         /// REQUIRED: The identifier of the customer to subscribe.

src/Stripe.net/Services/Subscriptions/StripeSubscriptionUpdateOptions.cs

@@ -44,15 +44,10 @@ internal string BillingCycleAnchorInternal
         [JsonProperty("items")]
         public List<StripeSubscriptionItemUpdateOption> Items { get; set; }
 
-        #region ProrationDate
-
         /// <summary>
         /// Boolean indicating whether this subscription should cancel at the end of the current period.
         /// </summary>
-        public DateTime? ProrationDate { get; set; }
-
         [JsonProperty("proration_date")]
-        internal string ProrationDateInternal => this.ProrationDate?.ConvertDateTimeToEpoch().ToString();
-        #endregion
+        public DateTime? ProrationDate { get; set; }
     }
 }

src/Stripe.net/Services/UsageRecords/StripeUsageRecordCreateOptions.cs

@@ -13,15 +13,10 @@ public class StripeUsageRecordCreateOptions : StripeBaseOptions
         [JsonIgnore]
         public string SubscriptionItem { get; set; }
 
-        public DateTime Timestamp { get; set; }
-
         [JsonProperty("timestamp")]
-        internal string TimestampInternal
-        {
-            get { return this.Timestamp.ConvertDateTimeToEpoch().ToString(); }
-        }
+        public DateTime Timestamp { get; set; }
 
         [JsonProperty("quantity")]
         public int Quantity { get; set; }
     }
-}
+}

src/StripeTests/Infrastructure/ParameterBuilderTest.cs

@@ -133,6 +133,16 @@ public void EncodesParameters()
                     want = "?bool=False&date_filter[lt]=946702800&date_filter[gte]=946684800&decimal=0&enum=test_one&int=0"
                 },
 
+                // DateTimeNullable
+                new
+                {
+                    data = new TestOptions
+                    {
+                        DateTimeNullable = DateTime.Parse("Sat, 01 Jan 2000 00:00:00Z"),
+                    },
+                    want = "?bool=False&datetime_nullable=946684800&decimal=0&enum=test_one&int=0"
+                },
+
                 // Decimal
                 new
                 {

src/StripeTests/Infrastructure/TestData/TestOptions.cs

@@ -35,6 +35,9 @@ public enum TestEnum
         [JsonProperty("date_filter")]
         public StripeDateFilter DateFilter { get; set; }
 
+        [JsonProperty("datetime_nullable")]
+        public DateTime? DateTimeNullable { get; set; }
+
         [JsonProperty("decimal")]
         public decimal Decimal { get; set; }